1 00:00:01,280 --> 00:00:04,320 Speaker 1: Welcome to Stuff You Missed in History Class, a production 2 00:00:04,360 --> 00:00:13,440 Speaker 1: of I Heart Radio. Hello, and welcome to the podcast. 3 00:00:13,440 --> 00:00:17,520 Speaker 1: I'm Holly Fry, and I'm Tracy Vie Wilson. Tracy, I 4 00:00:17,560 --> 00:00:20,320 Speaker 1: bet this happened to you. I know it happened to me. 5 00:00:20,440 --> 00:00:23,040 Speaker 1: Like you must have had those moments as a child 6 00:00:23,120 --> 00:00:25,040 Speaker 1: where you thought you were being very insightful. I know 7 00:00:25,079 --> 00:00:27,040 Speaker 1: I certainly did where I was like, how do I 8 00:00:27,120 --> 00:00:29,240 Speaker 1: know that what I see is the same thing as 9 00:00:29,280 --> 00:00:33,360 Speaker 1: other people see? I had this exact Yes. Yes, I 10 00:00:33,400 --> 00:00:35,480 Speaker 1: also asked my mom one time. I was like, Mom, 11 00:00:35,560 --> 00:00:38,600 Speaker 1: how do how do we know that what I see 12 00:00:38,640 --> 00:00:41,520 Speaker 1: as green is the same thing as what you see 13 00:00:41,560 --> 00:00:46,959 Speaker 1: as green? Uh? And my mom, stay at home mom 14 00:00:47,000 --> 00:00:48,919 Speaker 1: with two little children, did not always have a lot 15 00:00:48,960 --> 00:00:51,720 Speaker 1: of patients for weird questions. And she was like, it's 16 00:00:51,760 --> 00:00:59,200 Speaker 1: the same. I'm not trying to drag my mom in 17 00:00:59,240 --> 00:01:04,399 Speaker 1: any way. I'm know of our creativity and attentive to 18 00:01:04,520 --> 00:01:06,479 Speaker 1: our but yeah, this was a case where I liked 19 00:01:06,520 --> 00:01:08,880 Speaker 1: I just asked her a question she was not prepared 20 00:01:08,920 --> 00:01:13,160 Speaker 1: for question time. Here is the thing. I asked the 21 00:01:13,240 --> 00:01:17,840 Speaker 1: same question of my father, who I did not know, 22 00:01:19,160 --> 00:01:21,199 Speaker 1: and I don't know that he knew at the time 23 00:01:21,880 --> 00:01:28,039 Speaker 1: did not see color the way, so so he was 24 00:01:28,160 --> 00:01:31,160 Speaker 1: trying to describe things, and I just remember, I mean, 25 00:01:31,200 --> 00:01:33,360 Speaker 1: I was probably like seven or eight, already kind of 26 00:01:33,360 --> 00:01:35,200 Speaker 1: a smart alic, and I was just like, okay, this 27 00:01:35,280 --> 00:01:37,560 Speaker 1: is going nowhere. I'm out. So maybe just saying green 28 00:01:37,680 --> 00:01:39,959 Speaker 1: is green was a really a better route because that 29 00:01:40,080 --> 00:01:43,039 Speaker 1: led to a lot of confusion in our lives, um 30 00:01:43,160 --> 00:01:46,280 Speaker 1: for a moment, until we finally put the pieces together right. 31 00:01:46,640 --> 00:01:48,800 Speaker 1: And really what happened was that. And I don't mean 32 00:01:48,800 --> 00:01:51,760 Speaker 1: to drag my father, but like he was career military, 33 00:01:51,920 --> 00:01:55,560 Speaker 1: so um, he's now retired, but his clothes were like 34 00:01:55,640 --> 00:02:00,600 Speaker 1: sort of prescribed for sure. When he stopped up being 35 00:02:00,880 --> 00:02:04,480 Speaker 1: constantly on active duty and started picking out his own clothes, 36 00:02:04,520 --> 00:02:09,520 Speaker 1: some things became readily apparent, which is that that does 37 00:02:09,560 --> 00:02:12,200 Speaker 1: not go together. My dude, Yes, they look they're practically 38 00:02:12,280 --> 00:02:16,160 Speaker 1: the same color. Oh, we should address this, right. That's 39 00:02:16,520 --> 00:02:20,079 Speaker 1: we never knew for years, when you're wearing like jeans 40 00:02:20,280 --> 00:02:22,600 Speaker 1: and a plaid shirt in your off time and then 41 00:02:22,600 --> 00:02:25,040 Speaker 1: a uniform the rest of the time, it would never 42 00:02:25,040 --> 00:02:29,680 Speaker 1: come up. Now we learned. But this curiosity about whether 43 00:02:29,760 --> 00:02:32,800 Speaker 1: other people see the way that you see is really 44 00:02:32,800 --> 00:02:35,800 Speaker 1: what drives a lot of scientific discovery. Uh And we 45 00:02:35,840 --> 00:02:38,360 Speaker 1: are talking about somebody who was curious and did a 46 00:02:38,400 --> 00:02:42,320 Speaker 1: lot of scientific discovery. But in the case of this subject, 47 00:02:42,760 --> 00:02:45,560 Speaker 1: who was very well known and respected in his day, 48 00:02:45,880 --> 00:02:48,399 Speaker 1: he just didn't think about how he or anyone else 49 00:02:48,400 --> 00:02:52,320 Speaker 1: saw color until he kind of stumbled into it while 50 00:02:52,360 --> 00:02:55,760 Speaker 1: studying plants and realizing that his vision might be different 51 00:02:55,760 --> 00:02:58,680 Speaker 1: from other people. And that's John Dalton. And really John 52 00:02:58,720 --> 00:03:01,520 Speaker 1: Dalton is far more famous for his work in atomic 53 00:03:01,560 --> 00:03:05,880 Speaker 1: theory and which builds the foundations of organic chemistry, but 54 00:03:06,160 --> 00:03:09,520 Speaker 1: he also wrote one of the first really thorough descriptions 55 00:03:09,520 --> 00:03:13,040 Speaker 1: of what he called anomalous vision, meaning that he realized 56 00:03:13,080 --> 00:03:15,600 Speaker 1: he was not perceiving color in the same way as 57 00:03:15,639 --> 00:03:19,000 Speaker 1: other people. And his descriptions are very entertaining. We're going 58 00:03:19,040 --> 00:03:21,320 Speaker 1: to read some of them. Uh So today we will 59 00:03:21,360 --> 00:03:24,480 Speaker 1: talk a little bit about his life, but mostly about 60 00:03:24,560 --> 00:03:28,520 Speaker 1: this sort of pocket in his scientific work, where he 61 00:03:28,560 --> 00:03:31,840 Speaker 1: made a brief foray into exploring the world of photoreceptors 62 00:03:31,919 --> 00:03:34,920 Speaker 1: and color perception, although he didn't use those words for it. 63 00:03:35,680 --> 00:03:38,680 Speaker 1: Color blindness is a term that's falling out of favor 64 00:03:38,720 --> 00:03:42,400 Speaker 1: because it's not really accurate color blind suggests that somebody 65 00:03:42,400 --> 00:03:45,360 Speaker 1: can't see color at all. But most people who have 66 00:03:45,480 --> 00:03:49,520 Speaker 1: historically been diagnosed with color blindness can see colors, they 67 00:03:49,520 --> 00:03:53,680 Speaker 1: just see them differently. So defective color vision or color 68 00:03:53,840 --> 00:03:58,680 Speaker 1: vision deficiency are becoming more preferred terms. I feel like 69 00:03:58,720 --> 00:04:01,960 Speaker 1: I see people describing them selves as color blind still 70 00:04:02,360 --> 00:04:05,200 Speaker 1: quite a lot, So this is something that's evolving. We're 71 00:04:05,280 --> 00:04:08,000 Speaker 1: still kind of at the beginning of the scientific community 72 00:04:08,040 --> 00:04:12,160 Speaker 1: shifting to these different terms just and it's really about 73 00:04:12,160 --> 00:04:15,840 Speaker 1: clarity more than anything else, right, Like, now you do 74 00:04:16,040 --> 00:04:19,720 Speaker 1: see color. We'll talk about one exception, but just differently. 75 00:04:19,800 --> 00:04:21,920 Speaker 1: So we need to make a clearer term for it 76 00:04:21,960 --> 00:04:26,720 Speaker 1: that's not misleading. And color vision deficiency is the inability 77 00:04:26,800 --> 00:04:30,719 Speaker 1: to distinguish specific colors red, green, and blue, and to 78 00:04:30,760 --> 00:04:34,640 Speaker 1: be diagnosed as color blind historically or color vision deficient. Now, 79 00:04:34,960 --> 00:04:38,240 Speaker 1: a person only needs to have an inability to distinguish 80 00:04:38,320 --> 00:04:41,279 Speaker 1: one of these colors, but it is possible for someone 81 00:04:41,320 --> 00:04:44,560 Speaker 1: who has color vision deficiency to be unable to distinguish 82 00:04:44,600 --> 00:04:49,640 Speaker 1: all three. So in your retina, you have cells called rods, 83 00:04:49,680 --> 00:04:53,400 Speaker 1: which perceive light, and then three types of cells called cones. 84 00:04:54,120 --> 00:04:56,760 Speaker 1: Cones are really the important factor. Here. They are the 85 00:04:56,800 --> 00:05:01,120 Speaker 1: photoreceptive cells that enable us to perceive color. The human 86 00:05:01,160 --> 00:05:06,080 Speaker 1: retina contains six million cones. Red sensing cones make up 87 00:05:06,200 --> 00:05:11,120 Speaker 1: sixty of the total number of cone cells, green sensing 88 00:05:11,160 --> 00:05:14,880 Speaker 1: cones make up and blue sensing tones make up the 89 00:05:14,920 --> 00:05:18,080 Speaker 1: remaining ten. So if all of your cone cells are 90 00:05:18,120 --> 00:05:21,599 Speaker 1: functioning normally, you are said to have trichromacy, meaning you 91 00:05:21,640 --> 00:05:24,880 Speaker 1: can see three try of these colors and they combine 92 00:05:24,960 --> 00:05:28,719 Speaker 1: to create standard vision. But it is also possible to 93 00:05:28,760 --> 00:05:31,960 Speaker 1: have dichromacy with only two types of cone cells present 94 00:05:32,080 --> 00:05:35,800 Speaker 1: or functioning, or even monochromacy where only one type of 95 00:05:35,800 --> 00:05:39,360 Speaker 1: cone is functioning. Monochromacy is a little bit tricky because 96 00:05:39,360 --> 00:05:42,000 Speaker 1: it can also be used to describe a scenario where 97 00:05:42,080 --> 00:05:45,119 Speaker 1: none of a person's cones are functioning, and a person 98 00:05:45,160 --> 00:05:48,159 Speaker 1: who has monochromacy may have other vision issues as well, 99 00:05:48,360 --> 00:05:51,200 Speaker 1: And monochromacy that we just talked about with no cone 100 00:05:51,200 --> 00:05:54,080 Speaker 1: function is kind of the one variation in all of 101 00:05:54,080 --> 00:05:57,560 Speaker 1: this where the color blind label would be actually pretty accurate, 102 00:05:57,640 --> 00:06:01,640 Speaker 1: because everything to them appears not in the rainbow of colors, 103 00:06:01,640 --> 00:06:04,160 Speaker 1: but as a shade of gray most of the time. 104 00:06:04,240 --> 00:06:07,800 Speaker 1: Dichromacy manifests itself in a way that a person can't 105 00:06:07,839 --> 00:06:12,719 Speaker 1: see a difference between red and green, and dichromacy of 106 00:06:12,760 --> 00:06:16,280 Speaker 1: this nature is broken down into separate classifications based on 107 00:06:16,440 --> 00:06:19,120 Speaker 1: which types of cones do and don't work in a 108 00:06:19,160 --> 00:06:23,640 Speaker 1: person's retina. Protnopia describes a state of not being able 109 00:06:23,680 --> 00:06:26,680 Speaker 1: to see red, and due to anopia is a case 110 00:06:26,680 --> 00:06:30,200 Speaker 1: where the red cones functioned but the green cones do not. 111 00:06:30,960 --> 00:06:34,039 Speaker 1: Blue yellow color deficiency, which is a little rarer, is 112 00:06:34,120 --> 00:06:37,839 Speaker 1: similarly broken down into classifications based on its specific nature 113 00:06:37,839 --> 00:06:40,480 Speaker 1: in a given person. So someone with a lack of 114 00:06:40,520 --> 00:06:43,440 Speaker 1: blue cones is said to have tritenopia, and if they 115 00:06:43,440 --> 00:06:46,560 Speaker 1: have blue cones but reduced sensitivity to that color, it 116 00:06:46,640 --> 00:06:50,440 Speaker 1: is actually described as trite Anomally, and all color vision 117 00:06:50,480 --> 00:06:53,839 Speaker 1: deficiency can fall on a spectrum. Some people have a 118 00:06:53,880 --> 00:06:57,839 Speaker 1: diminished ability to distinguish red from green, for example, but 119 00:06:58,040 --> 00:07:03,160 Speaker 1: they're able to see difference then specific shades of these colors. Yeah, 120 00:07:03,200 --> 00:07:05,560 Speaker 1: sometimes you know, people can't hit the lighter tones of 121 00:07:05,600 --> 00:07:08,039 Speaker 1: the darker tones get real muddy, but they can see 122 00:07:08,200 --> 00:07:11,679 Speaker 1: different shades. It's it's all. It manifests in many different 123 00:07:11,680 --> 00:07:14,920 Speaker 1: ways and in the United States and estimated five to 124 00:07:15,040 --> 00:07:18,760 Speaker 1: ten of the population have some form of color vision deficiency. 125 00:07:20,240 --> 00:07:23,320 Speaker 1: Usually this gets tested for when people are kids, and 126 00:07:23,400 --> 00:07:27,000 Speaker 1: more boys than girls have colored vision deficiency, and the 127 00:07:27,040 --> 00:07:30,240 Speaker 1: percentage shifts based on race. So there was a twenty 128 00:07:30,280 --> 00:07:33,040 Speaker 1: fourteen study that gets cited a lot uh. This was 129 00:07:33,080 --> 00:07:37,080 Speaker 1: published in the journal Optimology, and it had taken studies 130 00:07:37,160 --> 00:07:41,040 Speaker 1: of the color vision of four thousand California children ranging 131 00:07:41,080 --> 00:07:44,200 Speaker 1: in age from three to six. And in this study 132 00:07:44,240 --> 00:07:46,520 Speaker 1: it was found that among the girls, less than half 133 00:07:46,520 --> 00:07:49,600 Speaker 1: a percent of them exhibited signs of color vision deficiency 134 00:07:49,640 --> 00:07:53,000 Speaker 1: regardless of race, but in boys the numbers were different. 135 00:07:53,520 --> 00:07:55,960 Speaker 1: Six percent of the white boys in the study were 136 00:07:55,960 --> 00:07:59,720 Speaker 1: diagnosed with color vision deficiency, three percent of the Asian 137 00:07:59,720 --> 00:08:02,920 Speaker 1: boy had some form of color vision deficiency. It was 138 00:08:02,960 --> 00:08:05,760 Speaker 1: found in fewer than three percent of the Latino boys 139 00:08:05,840 --> 00:08:10,080 Speaker 1: and less than two percent of black boys. Genetically, boys 140 00:08:10,200 --> 00:08:14,040 Speaker 1: are more likely to have red green color vision deficiency 141 00:08:14,080 --> 00:08:17,040 Speaker 1: because they only need to inherit it from their mother. 142 00:08:17,720 --> 00:08:23,160 Speaker 1: It is a recessive characteristic that's associated with the X chromosome. 143 00:08:23,880 --> 00:08:28,480 Speaker 1: So if a female inherits the trait from her mother 144 00:08:28,640 --> 00:08:32,360 Speaker 1: but not her father, she'll generally have normal color vision. 145 00:08:33,160 --> 00:08:37,120 Speaker 1: She only has that one X chromosome, but then she 146 00:08:37,160 --> 00:08:39,760 Speaker 1: could pass a trait onto her own children. And this 147 00:08:39,840 --> 00:08:42,959 Speaker 1: is different from blue yellow color vision deficiency, which is 148 00:08:43,000 --> 00:08:45,640 Speaker 1: a dominant characteristic, and so that only needs to be 149 00:08:45,679 --> 00:08:49,000 Speaker 1: inherited from one parent, and it is not linked to 150 00:08:49,080 --> 00:08:53,480 Speaker 1: a person's sex. I'm just gonna say these are related 151 00:08:53,520 --> 00:08:58,600 Speaker 1: to sex and not to gender. That's the different thing. Yeah, 152 00:08:58,640 --> 00:09:01,439 Speaker 1: we're going with kind of that twenty fourteen studies separation 153 00:09:01,480 --> 00:09:04,400 Speaker 1: of boys and girls, which simplifies the whole discussion, and 154 00:09:04,480 --> 00:09:09,800 Speaker 1: is sex assigned at birth not necessarily? How if they 155 00:09:09,800 --> 00:09:11,800 Speaker 1: did that, I would be fascinated if they did the 156 00:09:11,840 --> 00:09:14,640 Speaker 1: same exact test today and how they would break it out, 157 00:09:14,720 --> 00:09:18,040 Speaker 1: because it's things have shifted a bit um. So if 158 00:09:18,080 --> 00:09:20,720 Speaker 1: anybody knows of any studies similar to that going on today, 159 00:09:20,840 --> 00:09:24,360 Speaker 1: I'm very curious. But here's the thing. You're probably wondering, 160 00:09:24,400 --> 00:09:26,760 Speaker 1: how we figured all of this out? Uh. And in 161 00:09:26,800 --> 00:09:30,120 Speaker 1: the late eighteenth century, this idea of people perceiving color 162 00:09:30,280 --> 00:09:34,560 Speaker 1: differently than most humans was certainly not unknown. King George 163 00:09:34,600 --> 00:09:38,400 Speaker 1: the Third, for example, reportedly discussed this with an English novelist, 164 00:09:38,679 --> 00:09:42,480 Speaker 1: Fannie Bernie at court in seventeen eighty five, and there 165 00:09:42,480 --> 00:09:46,040 Speaker 1: were some theories about what caused color vision anomalies published 166 00:09:46,040 --> 00:09:48,720 Speaker 1: in Germany in the late seventeen hundreds, but the first 167 00:09:48,720 --> 00:09:53,440 Speaker 1: systematic analysis of color vision deficiency appears in seventeen at 168 00:09:53,480 --> 00:09:55,720 Speaker 1: least the first that we know of, and that brings 169 00:09:55,840 --> 00:09:57,480 Speaker 1: us to the person we mentioned at the top of 170 00:09:57,520 --> 00:10:01,000 Speaker 1: the show, John Dalton. John Dalton was born in early 171 00:10:01,040 --> 00:10:04,840 Speaker 1: September seventeen sixty six. His actual date of birth is 172 00:10:04,880 --> 00:10:09,800 Speaker 1: either September five or September six. His parents, Joseph Dalton 173 00:10:10,000 --> 00:10:13,440 Speaker 1: and Deborah green Up Dalton, were Quakers. His father made 174 00:10:13,440 --> 00:10:16,520 Speaker 1: a living as a weaver. The Dalton's had three children 175 00:10:16,559 --> 00:10:20,040 Speaker 1: who lived to adulthood, and John was the youngest of them. 176 00:10:20,120 --> 00:10:23,560 Speaker 1: And as a child, John attended a Quaker school, and 177 00:10:23,600 --> 00:10:27,240 Speaker 1: that school changed hands when John was twelve. John Fletcher, 178 00:10:27,320 --> 00:10:29,440 Speaker 1: the man who had been running it, gave it to 179 00:10:29,559 --> 00:10:33,480 Speaker 1: John Dalton's older brother, Jonathan Dalton, and then Jonathan enlisted 180 00:10:33,559 --> 00:10:36,839 Speaker 1: John's assistance in this new role, and this set John 181 00:10:36,840 --> 00:10:39,880 Speaker 1: on a path as an educator. Just kind of delights 182 00:10:39,920 --> 00:10:44,240 Speaker 1: me that they had a John and a Jonathan. It 183 00:10:44,320 --> 00:10:47,800 Speaker 1: makes me giggle as well. John and Jonathan expanded their 184 00:10:47,840 --> 00:10:50,840 Speaker 1: new careers by taking over a school in Kendall, England, 185 00:10:50,960 --> 00:10:54,920 Speaker 1: when John was just fourteen. This is a larger operation 186 00:10:55,080 --> 00:10:57,640 Speaker 1: than the Quaker grammar school they had been running, and 187 00:10:57,679 --> 00:11:01,120 Speaker 1: it included students who boarded as well as students. Has 188 00:11:01,120 --> 00:11:05,280 Speaker 1: totaled about five dozen students in all, and John was 189 00:11:05,320 --> 00:11:07,600 Speaker 1: sort of learning on a job. He was studying with 190 00:11:07,640 --> 00:11:11,200 Speaker 1: scholars to learn math, Latin, Greek and science to stay 191 00:11:11,240 --> 00:11:13,520 Speaker 1: ahead of his students and to be able to speak 192 00:11:13,520 --> 00:11:16,920 Speaker 1: on the subjects of their curriculum. And keep in mind, 193 00:11:16,960 --> 00:11:21,240 Speaker 1: again he's like fourteen fifteen at this fight, uh, so 194 00:11:21,280 --> 00:11:23,839 Speaker 1: he is taking in a lot of information. And he 195 00:11:24,040 --> 00:11:26,160 Speaker 1: stayed in that job for a dozen years and then 196 00:11:26,200 --> 00:11:28,719 Speaker 1: at the age of twenty seven, John moved on to 197 00:11:28,800 --> 00:11:32,280 Speaker 1: a new professional post as a mathematics teacher at New College, 198 00:11:32,280 --> 00:11:34,920 Speaker 1: and this was in Manchester. And he found all this 199 00:11:34,960 --> 00:11:37,800 Speaker 1: a little bit frustrating though, because his workload in that 200 00:11:37,920 --> 00:11:40,960 Speaker 1: job prevented him from having time to pursue his own 201 00:11:41,000 --> 00:11:44,920 Speaker 1: scientific study. So he switched gears and decided that he 202 00:11:44,920 --> 00:11:47,400 Speaker 1: would become a private tutor so that he could manage 203 00:11:47,400 --> 00:11:49,640 Speaker 1: his own time in a way that would enable him 204 00:11:49,679 --> 00:11:52,480 Speaker 1: to carry on with his side work. At this point, 205 00:11:52,520 --> 00:11:55,640 Speaker 1: his work outside of his daily teaching task was focused 206 00:11:55,760 --> 00:11:59,240 Speaker 1: largely on meteorology. He had been publishing articles in the 207 00:11:59,280 --> 00:12:03,199 Speaker 1: subject for several years, but he kept studying other sciences 208 00:12:03,240 --> 00:12:06,520 Speaker 1: as well and all and it was through these studies 209 00:12:06,559 --> 00:12:09,120 Speaker 1: that he wound up writing a paper that expounded on 210 00:12:09,200 --> 00:12:13,679 Speaker 1: the idea that not everyone saw colors in the same way. 211 00:12:13,720 --> 00:12:16,360 Speaker 1: So this was not the first time the mention of 212 00:12:16,400 --> 00:12:20,640 Speaker 1: non standard color vision appeared in print. As we said earlier, surely, 213 00:12:20,720 --> 00:12:23,720 Speaker 1: color vision divisiency has been in play almost as long 214 00:12:23,760 --> 00:12:26,920 Speaker 1: as humans have existed, and even before Dalton there had 215 00:12:27,000 --> 00:12:30,360 Speaker 1: been some mentions of it, including a write up of 216 00:12:30,400 --> 00:12:33,320 Speaker 1: a man named Thomas Harris that was published in Philosophical 217 00:12:33,320 --> 00:12:38,480 Speaker 1: Transactions and that described Harris's inability to distinguish colors, which 218 00:12:38,679 --> 00:12:41,880 Speaker 1: was published in seventeen seventy seven. We're gonna come back 219 00:12:41,880 --> 00:12:44,480 Speaker 1: to Harris, and we'll talk first more about John Dalton, 220 00:12:44,720 --> 00:12:46,120 Speaker 1: but before we do all of that, we're going to 221 00:12:46,200 --> 00:12:57,320 Speaker 1: pause for a brief sponsor break. John Dalton presented his paper, 222 00:12:57,400 --> 00:13:00,280 Speaker 1: which was titled Extraordinary Facts relating to the s of 223 00:13:00,320 --> 00:13:04,920 Speaker 1: Colors with Observations by Mr John Dalton, at Manchester's Literary 224 00:13:05,000 --> 00:13:10,880 Speaker 1: and Philosophical Society on October. He had joined the society 225 00:13:10,960 --> 00:13:14,520 Speaker 1: upon moving to Manchester. And as scientific papers go, this 226 00:13:14,559 --> 00:13:17,200 Speaker 1: one is kind of unique in that Dalton himself is 227 00:13:17,240 --> 00:13:19,280 Speaker 1: really the subject of the paper, or at least his 228 00:13:19,559 --> 00:13:23,600 Speaker 1: vision was. That text opens with quote, it has been 229 00:13:23,640 --> 00:13:28,200 Speaker 1: observed that our ideas of colors sounds, tastes, et cetera, 230 00:13:28,840 --> 00:13:32,600 Speaker 1: excited by the same object, may be very different in 231 00:13:32,640 --> 00:13:35,880 Speaker 1: themselves without our being aware of it. He goes on, 232 00:13:36,040 --> 00:13:38,880 Speaker 1: quote I was always of the opinion, though I might 233 00:13:38,960 --> 00:13:43,880 Speaker 1: not often mention it, that several colors were injudiciously named. 234 00:13:44,679 --> 00:13:47,840 Speaker 1: The term pink, in reference to the flower of that name, 235 00:13:47,880 --> 00:13:52,280 Speaker 1: seemed proper enough. But when the term red was substituted 236 00:13:52,320 --> 00:13:55,480 Speaker 1: for pink, I thought it highly improper. It should have 237 00:13:55,600 --> 00:13:59,400 Speaker 1: been blue in my apprehension, as pink and blue appear 238 00:13:59,520 --> 00:14:03,320 Speaker 1: to me very nearly allied, whilst pink and red have 239 00:14:03,520 --> 00:14:09,120 Speaker 1: scarcely any relation. He goes on in his introduction to 240 00:14:09,160 --> 00:14:11,840 Speaker 1: mention how he had learned about light and optics in 241 00:14:11,880 --> 00:14:14,760 Speaker 1: his scientific studies, but he hadn't really thought about applying 242 00:14:14,840 --> 00:14:18,560 Speaker 1: any of that information to colors, because that entire area 243 00:14:18,720 --> 00:14:21,480 Speaker 1: the idea of color seemed kind of confused, And on 244 00:14:21,680 --> 00:14:23,400 Speaker 1: to them like he really was, like, why would people 245 00:14:23,400 --> 00:14:26,040 Speaker 1: group these colors together? Doesn't make any sense, But I 246 00:14:26,080 --> 00:14:28,560 Speaker 1: guess that's how we've always done it. Uh. It was 247 00:14:28,600 --> 00:14:32,000 Speaker 1: not until he turned his scientific work to botany that 248 00:14:32,120 --> 00:14:35,200 Speaker 1: he really started thinking about why some color groupings just 249 00:14:35,320 --> 00:14:38,760 Speaker 1: made no sense. And this study prompted him to ask 250 00:14:38,800 --> 00:14:42,840 Speaker 1: other people questions about colors. He actually uses the example 251 00:14:43,120 --> 00:14:46,040 Speaker 1: in this paper of asking a person whether a flower 252 00:14:46,160 --> 00:14:48,960 Speaker 1: was blue or pink. But they always just thought he 253 00:14:49,040 --> 00:14:51,480 Speaker 1: must be joking because the queries came off as so 254 00:14:51,560 --> 00:14:54,440 Speaker 1: completely absurd to them. So he just thought everybody had 255 00:14:54,440 --> 00:14:59,120 Speaker 1: this weird relationship with color. Even though he thought colors 256 00:14:59,200 --> 00:15:01,880 Speaker 1: made no sense, it didn't really occur to him to 257 00:15:01,960 --> 00:15:05,560 Speaker 1: wonder if there was something unusual about the way he 258 00:15:05,640 --> 00:15:10,160 Speaker 1: was perceiving colors. It was a moment in seventeen ninety two, 259 00:15:10,440 --> 00:15:13,040 Speaker 1: two years before he presented his paper, that really gave 260 00:15:13,120 --> 00:15:17,040 Speaker 1: him this moment of pause. That moment happened when he 261 00:15:17,120 --> 00:15:20,920 Speaker 1: was looking at a geranium by candle light. So he 262 00:15:20,960 --> 00:15:24,280 Speaker 1: had frequently seen these flowers, this particular variety he was 263 00:15:24,320 --> 00:15:28,000 Speaker 1: looking at were in fact pink in daylight, and to him, 264 00:15:28,040 --> 00:15:31,520 Speaker 1: in daylight he perceived them as sky blue, but by 265 00:15:31,600 --> 00:15:34,800 Speaker 1: candle light, he saw this flower as a vibrant red, 266 00:15:35,360 --> 00:15:38,080 Speaker 1: and this significant shift in their color due to lighting 267 00:15:38,160 --> 00:15:42,240 Speaker 1: changes startled him and led him to make a quick 268 00:15:42,280 --> 00:15:44,760 Speaker 1: study by asking a number of friends to look at 269 00:15:44,800 --> 00:15:48,640 Speaker 1: these same flowers in both daylight and candle light. All 270 00:15:48,720 --> 00:15:50,880 Speaker 1: the people he initially asked about it saw them as 271 00:15:50,920 --> 00:15:54,880 Speaker 1: pink in both lighting conditions, except for his brother, who 272 00:15:54,920 --> 00:15:57,800 Speaker 1: perceived that same shift of them being sky blue in 273 00:15:57,840 --> 00:16:01,600 Speaker 1: the day and red in candle light. This experience caused 274 00:16:01,640 --> 00:16:04,920 Speaker 1: him to start a more structured study of light and color, 275 00:16:05,400 --> 00:16:08,200 Speaker 1: which he did with an assistant who had quote normal 276 00:16:08,360 --> 00:16:12,720 Speaker 1: color vision. First, he used a prism to project sunlight 277 00:16:12,760 --> 00:16:15,400 Speaker 1: into a dark room and then recorded the number of 278 00:16:15,440 --> 00:16:18,120 Speaker 1: colors that various people saw in that band of light. 279 00:16:18,240 --> 00:16:22,400 Speaker 1: Most of them saw six red, orange, yellow, green, blue, 280 00:16:22,400 --> 00:16:26,000 Speaker 1: and purple. He does mention that purple is separated into 281 00:16:26,040 --> 00:16:30,640 Speaker 1: indigo in violet and Newton's writings on color for the 282 00:16:30,640 --> 00:16:33,840 Speaker 1: purposes of a person simply looking at a band of light, 283 00:16:34,360 --> 00:16:37,360 Speaker 1: that distinction is really nominal. I think we talked about 284 00:16:37,360 --> 00:16:39,680 Speaker 1: this in one of our episodes that touched on Newton. Previously. 285 00:16:39,840 --> 00:16:42,160 Speaker 1: He put the indigo and violet in their separately because 286 00:16:42,160 --> 00:16:46,320 Speaker 1: he wanted there to be seven. So that's why people 287 00:16:46,360 --> 00:16:49,320 Speaker 1: typically don't actually see them. As to the state shades 288 00:16:49,360 --> 00:16:52,760 Speaker 1: in light from a prism, yeah, or you'll see what 289 00:16:52,920 --> 00:16:55,440 Speaker 1: you think is maybe a slight difference, but it's hard 290 00:16:55,480 --> 00:16:59,640 Speaker 1: to be sure. So for for Dalton, he just called 291 00:16:59,680 --> 00:17:02,920 Speaker 1: that one thing, it's purple. Uh. When Dalton looked at 292 00:17:02,920 --> 00:17:06,120 Speaker 1: the prismatic light, though, he could only make out two 293 00:17:06,240 --> 00:17:10,520 Speaker 1: or sometimes three colors, so generally he just saw yellow 294 00:17:10,600 --> 00:17:14,199 Speaker 1: and blue, or sometimes he would see yellow, blue, and 295 00:17:14,359 --> 00:17:17,199 Speaker 1: a little bit of purple. And through his work he 296 00:17:17,240 --> 00:17:19,720 Speaker 1: identified that the band that he saw is yellow was 297 00:17:19,760 --> 00:17:22,720 Speaker 1: where other people were seeing red, orange, yellow, and green, 298 00:17:23,520 --> 00:17:25,640 Speaker 1: and he wrote quote that part of the image, which 299 00:17:25,680 --> 00:17:28,359 Speaker 1: others call red, appears to me little more than a 300 00:17:28,440 --> 00:17:32,679 Speaker 1: shade or a defective light. After that, the orange, yellow, 301 00:17:32,720 --> 00:17:36,360 Speaker 1: and green seemed one color which descends pretty uniformly from 302 00:17:36,359 --> 00:17:39,679 Speaker 1: an intense to a rare yellow, making what I should 303 00:17:39,680 --> 00:17:43,359 Speaker 1: call different shades of yellow. Dalton's perception of blue and 304 00:17:43,480 --> 00:17:46,639 Speaker 1: purple aligned with what other people were seeing, and the 305 00:17:46,720 --> 00:17:49,960 Speaker 1: contrast between the end of his band of yellow and 306 00:17:50,000 --> 00:17:53,440 Speaker 1: the adjacent blue was really sharp. So next he did 307 00:17:53,480 --> 00:17:57,320 Speaker 1: the same collecting of perceptions from himself and others when 308 00:17:57,359 --> 00:18:00,920 Speaker 1: looking at candle light projected through a prism, and these 309 00:18:00,920 --> 00:18:04,439 Speaker 1: results were mostly the same. The only exception that Dalton 310 00:18:04,520 --> 00:18:06,840 Speaker 1: calls out is that for him, the red edge of 311 00:18:06,840 --> 00:18:09,800 Speaker 1: the image looks more vivid in candle light than it 312 00:18:09,840 --> 00:18:13,000 Speaker 1: did looking at some light under the same conditions of 313 00:18:13,040 --> 00:18:16,480 Speaker 1: being put through a prism. Dalton's paper next breaks out 314 00:18:16,520 --> 00:18:20,600 Speaker 1: studies of specific colors as he had always perceived them. 315 00:18:20,640 --> 00:18:24,160 Speaker 1: He starts out by describing colors grouped with red as 316 00:18:24,160 --> 00:18:27,800 Speaker 1: they appear in the daylight versus candle light. His description 317 00:18:27,840 --> 00:18:32,160 Speaker 1: of crimson is pretty charming quote Crimson has a grave appearance, 318 00:18:32,240 --> 00:18:37,000 Speaker 1: being the reverse of every showy and splendid color. A 319 00:18:37,240 --> 00:18:40,760 Speaker 1: similarly quaint description this is a description of pink. He 320 00:18:40,840 --> 00:18:44,040 Speaker 1: breaks that down as nine parts light blue and one 321 00:18:44,119 --> 00:18:47,959 Speaker 1: part red quote or some other color which has no 322 00:18:48,080 --> 00:18:51,200 Speaker 1: other effect than to make the light blue appear dull 323 00:18:51,280 --> 00:18:54,439 Speaker 1: and faded a little. He also lists out all the 324 00:18:54,480 --> 00:18:57,359 Speaker 1: flowers that to him look blue to give the reader 325 00:18:57,400 --> 00:19:00,080 Speaker 1: a sense of context. When he says he says pinks 326 00:19:00,119 --> 00:19:04,159 Speaker 1: and reds as blue. Blood, he says appears to him 327 00:19:04,200 --> 00:19:07,160 Speaker 1: as the color most people call bottle green, and he 328 00:19:07,240 --> 00:19:10,480 Speaker 1: mentions that if he saw a light colored stocking that 329 00:19:10,640 --> 00:19:14,639 Speaker 1: was spattered with either fresh blood or dirt, he would 330 00:19:14,640 --> 00:19:18,720 Speaker 1: not be able to tell the difference visually. I love 331 00:19:18,800 --> 00:19:22,040 Speaker 1: this entire paper so much. It's exactly like this. The 332 00:19:22,080 --> 00:19:26,840 Speaker 1: way through his his turn of phrases, quite quite charming 333 00:19:26,840 --> 00:19:30,520 Speaker 1: and endearing, He goes on to describe the significant change 334 00:19:30,560 --> 00:19:33,400 Speaker 1: that red undergoes for him when viewed in candle light. 335 00:19:33,560 --> 00:19:35,840 Speaker 1: He describes it as much more vivid, and the blue 336 00:19:35,920 --> 00:19:39,600 Speaker 1: no longer being present and instead replaced by yellow tones. 337 00:19:40,400 --> 00:19:43,960 Speaker 1: While he found most reds and pinks quite drabbed by daylight, 338 00:19:44,200 --> 00:19:47,440 Speaker 1: in kindle light they became really vivid and even exciting. 339 00:19:48,200 --> 00:19:50,720 Speaker 1: Orange and yellow, he says, are not too different for 340 00:19:50,800 --> 00:19:54,600 Speaker 1: him than anyone else. When he moves on to discussing green, 341 00:19:54,920 --> 00:19:58,640 Speaker 1: he writes, quote, I take my standard idea from grass. 342 00:19:59,359 --> 00:20:02,080 Speaker 1: This appear is to me very little different from red. 343 00:20:02,480 --> 00:20:05,119 Speaker 1: The face of a laurel leaf is a good match 344 00:20:05,200 --> 00:20:08,240 Speaker 1: to a stick of ceiling wax, and so it will 345 00:20:08,280 --> 00:20:11,919 Speaker 1: be immediately concluded that I see either red or green, 346 00:20:12,119 --> 00:20:16,000 Speaker 1: or both different from other people. The fact is, I 347 00:20:16,040 --> 00:20:19,280 Speaker 1: believe that they both appear different to me from what 348 00:20:19,359 --> 00:20:23,760 Speaker 1: they do to others. He concludes that blues he generally 349 00:20:23,760 --> 00:20:26,359 Speaker 1: sees the same as other people, and purple is just 350 00:20:26,440 --> 00:20:30,080 Speaker 1: a little bit different from blue. He described brown in 351 00:20:30,119 --> 00:20:33,280 Speaker 1: the same creative way that he does other colors, writing quote, 352 00:20:33,600 --> 00:20:36,280 Speaker 1: my idea of brown I obtained from a piece of 353 00:20:36,320 --> 00:20:40,480 Speaker 1: white paper heated almost to ignition. He also notes that 354 00:20:40,520 --> 00:20:44,440 Speaker 1: seeing colors in moonlight presents the same or near same 355 00:20:44,480 --> 00:20:48,320 Speaker 1: results for him as seeing them in candlelight. Lightning gives 356 00:20:48,359 --> 00:20:51,600 Speaker 1: the same effect as daylight. It doesn't matter whether the 357 00:20:51,640 --> 00:20:54,520 Speaker 1: sun is rising or setting when it comes to color, 358 00:20:55,000 --> 00:20:58,960 Speaker 1: and any kind of combustible substance creates the same color 359 00:20:59,040 --> 00:21:02,800 Speaker 1: perception as any other flame. He concludes the section of 360 00:21:02,800 --> 00:21:05,640 Speaker 1: the paper with quote, my vision has always been as 361 00:21:05,680 --> 00:21:09,400 Speaker 1: it is now. His next section breaks out the information 362 00:21:09,480 --> 00:21:12,840 Speaker 1: that he's collected from other people and their perceptions of color, 363 00:21:13,280 --> 00:21:15,760 Speaker 1: starting with people he has found who have vision that 364 00:21:15,880 --> 00:21:20,240 Speaker 1: seems similar to his own, and Dalton mentions Mr Harris 365 00:21:20,240 --> 00:21:25,160 Speaker 1: of Maryport and his alternate perceptions of color. Dalton thought that, 366 00:21:25,240 --> 00:21:29,320 Speaker 1: based on the description, Harris's anomalous vision might have been 367 00:21:29,320 --> 00:21:32,760 Speaker 1: different from his own. He discovered that one of Harris's 368 00:21:32,800 --> 00:21:35,440 Speaker 1: brothers was still alive, so he made contact and went 369 00:21:35,480 --> 00:21:39,800 Speaker 1: to visit. Upon questioning this brother and testing his vision, 370 00:21:40,080 --> 00:21:42,760 Speaker 1: Dalton found that the Harris family seemed to have the 371 00:21:42,840 --> 00:21:46,720 Speaker 1: same genetic variable that he and his brother had when 372 00:21:46,720 --> 00:21:48,359 Speaker 1: it came to how they perceived the colors of the 373 00:21:48,359 --> 00:21:51,480 Speaker 1: world around them. This led to a general line of 374 00:21:51,560 --> 00:21:55,000 Speaker 1: questioning of the students and colleagues that Dalton regularly came 375 00:21:55,040 --> 00:21:57,720 Speaker 1: in contact with, kind of as a subject group, and 376 00:21:57,800 --> 00:22:00,760 Speaker 1: he found a small proportion of them share his specific 377 00:22:00,840 --> 00:22:04,480 Speaker 1: experience regarding pink and light blue looking similar by daylight 378 00:22:04,520 --> 00:22:08,439 Speaker 1: and different by candle light. Dalton also found just a 379 00:22:08,440 --> 00:22:11,040 Speaker 1: couple of examples of people who quote differ from the 380 00:22:11,080 --> 00:22:14,840 Speaker 1: generality and from us, also meaning that they seem to 381 00:22:14,880 --> 00:22:18,480 Speaker 1: have a different type of color vision deficiency. He also 382 00:22:18,560 --> 00:22:22,000 Speaker 1: mentioned a shared experience among all of these people that 383 00:22:22,160 --> 00:22:24,600 Speaker 1: justice with him it had not occurred to them that 384 00:22:24,640 --> 00:22:27,280 Speaker 1: they were seeing things differently from the majority of people, 385 00:22:27,680 --> 00:22:30,040 Speaker 1: but that they too found the names and groupings of 386 00:22:30,080 --> 00:22:33,919 Speaker 1: colors perplexing at times. Though his paper was really the 387 00:22:33,960 --> 00:22:38,520 Speaker 1: beginning of sciences study of color vision deficiency, even in 388 00:22:38,600 --> 00:22:42,800 Speaker 1: his really relatively small data set, Dalton was already capturing 389 00:22:42,840 --> 00:22:46,560 Speaker 1: information that showed a difference in instances of color vision 390 00:22:46,600 --> 00:22:50,520 Speaker 1: deficiency in regards to people's sex. He noted that in 391 00:22:50,560 --> 00:22:53,920 Speaker 1: the Harris family, four of six sons in the family 392 00:22:54,000 --> 00:22:56,960 Speaker 1: had what would come to be known as color vision deficiency, 393 00:22:57,119 --> 00:23:00,720 Speaker 1: sometimes also called dalton is um for obvious reason, but 394 00:23:00,760 --> 00:23:05,159 Speaker 1: their sister didn't. Similarly, Dalton and his brother Jonathan had 395 00:23:05,200 --> 00:23:09,600 Speaker 1: the same color experience, but their sister did not. He wrote, quote, 396 00:23:09,600 --> 00:23:11,760 Speaker 1: it is remarkable, but I have not heard of one 397 00:23:11,880 --> 00:23:16,320 Speaker 1: female subject to this peculiarity. He also included the line 398 00:23:16,400 --> 00:23:19,480 Speaker 1: quote I did not find that the parents or children 399 00:23:19,480 --> 00:23:22,080 Speaker 1: in any of these instances have been so unless in 400 00:23:22,200 --> 00:23:25,720 Speaker 1: one case. So, even though he didn't really realize it, 401 00:23:25,880 --> 00:23:29,320 Speaker 1: he was gathering information on the recessive genetic nature of 402 00:23:29,359 --> 00:23:32,720 Speaker 1: red green color vision deficiency. Next up, we'll talk about 403 00:23:32,720 --> 00:23:36,680 Speaker 1: what Dalton thought was causing his anomalous vision, but first 404 00:23:36,680 --> 00:23:39,080 Speaker 1: we will take a break for a word from our sponsors. 405 00:23:46,840 --> 00:23:49,960 Speaker 1: The third section of Dalton's paper tries to unravel the 406 00:23:50,040 --> 00:23:52,880 Speaker 1: cause of what he was referring to as quote our 407 00:23:52,960 --> 00:23:56,360 Speaker 1: anomalous vision. One of the ways that he worked out 408 00:23:56,400 --> 00:24:00,080 Speaker 1: his theory here was to work with transparent colored liquids, 409 00:24:00,119 --> 00:24:02,560 Speaker 1: and then he would have various people look at objects 410 00:24:02,600 --> 00:24:06,920 Speaker 1: through those transparent colored liquids to record their perception of color. 411 00:24:07,000 --> 00:24:09,159 Speaker 1: So he would hold up a thing behind, like a 412 00:24:09,240 --> 00:24:12,760 Speaker 1: tank of blue water, whatever um and ask them what 413 00:24:12,800 --> 00:24:15,600 Speaker 1: they saw. And because people with you know, quote unquote 414 00:24:15,600 --> 00:24:19,320 Speaker 1: normal vision described color similar to what he saw in 415 00:24:19,440 --> 00:24:23,120 Speaker 1: his normal day to day life when they looked through 416 00:24:23,160 --> 00:24:26,159 Speaker 1: a tank of blue water, he came to this incorrect 417 00:24:26,200 --> 00:24:29,760 Speaker 1: conclusion that quote, one of the humors of my eye 418 00:24:29,880 --> 00:24:34,159 Speaker 1: must be a transparent but colored medium, so constituted as 419 00:24:34,200 --> 00:24:37,760 Speaker 1: to absorb red and green rays principally because I obtain 420 00:24:37,880 --> 00:24:41,440 Speaker 1: no proper idea of these in the solar spectrum, and 421 00:24:41,600 --> 00:24:46,159 Speaker 1: to transmit blue and other colors more perfectly. Honestly, this 422 00:24:46,240 --> 00:24:53,040 Speaker 1: is a totally reasonable conclusion based on understanding. Right. He 423 00:24:53,160 --> 00:24:56,720 Speaker 1: outlined how this would impact the perception of various colors, 424 00:24:56,760 --> 00:25:00,359 Speaker 1: and then addressed why the colors changed so dressed for 425 00:25:00,480 --> 00:25:03,480 Speaker 1: him and other others like him. In candlelight, writing quote, 426 00:25:03,800 --> 00:25:06,760 Speaker 1: when any kind of light is less abundant in blue, 427 00:25:06,920 --> 00:25:09,560 Speaker 1: as is the case with candle light compared to daylight, 428 00:25:10,080 --> 00:25:13,960 Speaker 1: our eyes serve in some degree to temper that light 429 00:25:14,359 --> 00:25:17,359 Speaker 1: so as to reduce it nearly to the common standard. 430 00:25:17,960 --> 00:25:21,400 Speaker 1: The Earth's atmosphere, he believed was a blue fluid that 431 00:25:21,520 --> 00:25:25,520 Speaker 1: quote modifies the Sun's light so as to occasion the 432 00:25:25,680 --> 00:25:31,040 Speaker 1: commonly perceived difference. So this paper was met with some curiosity, 433 00:25:31,200 --> 00:25:34,359 Speaker 1: and his very detailed comparisons of his vision to that 434 00:25:34,440 --> 00:25:37,440 Speaker 1: of other people who saw color normally offered a lot 435 00:25:37,480 --> 00:25:40,919 Speaker 1: of insights. But this idea of a blue humor in 436 00:25:41,000 --> 00:25:43,679 Speaker 1: his eye that was causing his anomalous color vision was 437 00:25:43,840 --> 00:25:48,320 Speaker 1: kind of dismissed by the scientific community, and in response, Dalton, 438 00:25:48,400 --> 00:25:51,080 Speaker 1: who really thought he was onto something with it, donated 439 00:25:51,160 --> 00:25:54,560 Speaker 1: his eyes to science. He wrote up a document that 440 00:25:54,640 --> 00:25:58,280 Speaker 1: requested that his eyes be dissected upon his death to 441 00:25:58,280 --> 00:26:00,720 Speaker 1: see if he had been correct and whether there was 442 00:26:00,800 --> 00:26:03,879 Speaker 1: any other physical evidence to explain the way he perceived color. 443 00:26:04,560 --> 00:26:07,439 Speaker 1: A little less than a decade after Dalton's writing on 444 00:26:07,560 --> 00:26:12,520 Speaker 1: his anomalous vision, scientist Thomas Young published on the theory 445 00:26:12,560 --> 00:26:15,600 Speaker 1: of light and colors, and this put forth the idea 446 00:26:15,640 --> 00:26:18,600 Speaker 1: that there were receptors in the eye for each of 447 00:26:18,640 --> 00:26:22,199 Speaker 1: the colors red, green, and blue. So he was totally 448 00:26:22,200 --> 00:26:26,280 Speaker 1: onto it, and Young addressed Dalton's work and his anomalous 449 00:26:26,320 --> 00:26:29,399 Speaker 1: color vision with a different theory that there was a 450 00:26:29,480 --> 00:26:33,200 Speaker 1: quote absence or paralysis of those fibers of the retina 451 00:26:33,280 --> 00:26:37,760 Speaker 1: which are calculated to perceive red. He was so completely 452 00:26:37,800 --> 00:26:40,639 Speaker 1: on the right track that you would think that this 453 00:26:40,680 --> 00:26:43,560 Speaker 1: would have just broken eye science wide open. But no, no, 454 00:26:43,800 --> 00:26:47,880 Speaker 1: it advancement slowed down after this and studying the eye 455 00:26:47,920 --> 00:26:50,280 Speaker 1: and that went on for decades. Yeah, it was like 456 00:26:50,320 --> 00:26:52,359 Speaker 1: people are like neat idea and they moved on to 457 00:26:52,440 --> 00:26:56,399 Speaker 1: other stuff. Um Beyond the study of color vision deficiency. 458 00:26:56,560 --> 00:27:00,280 Speaker 1: John Dalton of course continued to make important contributions to 459 00:27:00,320 --> 00:27:04,600 Speaker 1: the scientific world. Concurrently, while working on figuring out why 460 00:27:04,640 --> 00:27:06,920 Speaker 1: he couldn't see flowers the same way as other people, 461 00:27:07,240 --> 00:27:11,360 Speaker 1: he also published a work titled Meteorological Observation and Essays. 462 00:27:12,160 --> 00:27:15,359 Speaker 1: He published additional work in meteorology as well, and his 463 00:27:15,440 --> 00:27:18,440 Speaker 1: work in this field led to some fellow scientists considering 464 00:27:18,520 --> 00:27:22,720 Speaker 1: him the father of meteorology, although his work. Anytime somebody 465 00:27:22,760 --> 00:27:24,480 Speaker 1: gets called the father of something, I always have to 466 00:27:24,520 --> 00:27:27,440 Speaker 1: go because his work was of course building on that 467 00:27:27,480 --> 00:27:29,919 Speaker 1: of his mentors on this subject. He had particularly had 468 00:27:29,920 --> 00:27:33,399 Speaker 1: a really good mentor in meteorology when he was studying 469 00:27:34,040 --> 00:27:37,480 Speaker 1: as a teacher. Dalton also did a lot of work 470 00:27:37,560 --> 00:27:42,600 Speaker 1: in chemistry, specifically atomic theory. His work in this area 471 00:27:42,680 --> 00:27:46,400 Speaker 1: came to some incorrect conclusions, but it was also instrumental 472 00:27:46,520 --> 00:27:49,960 Speaker 1: in moving the scientific community away from the long held 473 00:27:50,040 --> 00:27:53,600 Speaker 1: idea that matter was at the basic level all the 474 00:27:53,800 --> 00:27:58,680 Speaker 1: same and just configured differently to form different things. Dalton 475 00:27:59,040 --> 00:28:01,600 Speaker 1: championed the idea that there were all kinds of different 476 00:28:01,640 --> 00:28:05,160 Speaker 1: atoms with different sizes and weights, and that they behaved differently. 477 00:28:05,880 --> 00:28:08,560 Speaker 1: He started a project to measure the masses of different 478 00:28:08,600 --> 00:28:12,399 Speaker 1: atomic particles to begin cataloging all of the different atoms 479 00:28:12,400 --> 00:28:15,399 Speaker 1: that could be found. He presented the first table of 480 00:28:15,440 --> 00:28:18,119 Speaker 1: atomic weights in eighteen o three, and his work in 481 00:28:18,160 --> 00:28:21,760 Speaker 1: this area propelled organic chemistry forward. He is also sometimes 482 00:28:21,840 --> 00:28:25,720 Speaker 1: called the Father of chemistry. Dalton had joined the Manchester 483 00:28:26,000 --> 00:28:30,120 Speaker 1: Literary and Philosophical Society in seventee when he was still 484 00:28:30,119 --> 00:28:33,600 Speaker 1: in his twenties. In eighteen seventeen, as a man in 485 00:28:33,640 --> 00:28:37,320 Speaker 1: his early fifties, he became its president. He held this 486 00:28:37,400 --> 00:28:40,080 Speaker 1: position for the rest of his life. His scientific career 487 00:28:40,200 --> 00:28:43,320 Speaker 1: slowed down quite a bit. Yeah, there were some other 488 00:28:43,360 --> 00:28:46,280 Speaker 1: issues where his He had some papers that were denied 489 00:28:46,320 --> 00:28:49,800 Speaker 1: for publication, and it just wasn't like the heyday he 490 00:28:49,800 --> 00:28:52,040 Speaker 1: had had when he was a little younger. He had 491 00:28:52,040 --> 00:28:55,080 Speaker 1: a unique distinction though, of seeing for example, his own 492 00:28:55,080 --> 00:28:59,000 Speaker 1: statue erected in Manchester during his lifetime for his accomplishments, 493 00:28:59,240 --> 00:29:02,160 Speaker 1: and while he had been barred from an education at 494 00:29:02,160 --> 00:29:04,600 Speaker 1: Oxford or Cambridge as a young man because he was 495 00:29:04,600 --> 00:29:08,840 Speaker 1: a Quaker not an Anglican, he received honorary degrees from 496 00:29:08,880 --> 00:29:11,680 Speaker 1: both later in life. He also served as a foreign 497 00:29:11,680 --> 00:29:15,720 Speaker 1: Associate of the French Academy of Sciences. On April eighteenth, 498 00:29:15,800 --> 00:29:19,000 Speaker 1: eighteen thirty seven, Dalton, who was seventy at the time, 499 00:29:19,480 --> 00:29:22,960 Speaker 1: had a stroke that resulted in a partial paralysis, and 500 00:29:23,000 --> 00:29:26,240 Speaker 1: then he had another small stroke or possibly a seizure 501 00:29:26,400 --> 00:29:30,440 Speaker 1: several days later. Being pretty pragmatic, he set his affairs 502 00:29:30,480 --> 00:29:32,800 Speaker 1: in order as soon as he was recovered enough to 503 00:29:32,800 --> 00:29:35,920 Speaker 1: do so. But then he lived another seven years. He 504 00:29:36,000 --> 00:29:39,840 Speaker 1: continued as president of the Literary and Philosophical Society. He 505 00:29:39,960 --> 00:29:43,239 Speaker 1: made visits to Lake Country. That's something that he had 506 00:29:43,240 --> 00:29:45,720 Speaker 1: been doing throughout his life. Yeah, it was a very 507 00:29:45,720 --> 00:29:47,560 Speaker 1: close call, and then he kind of was like, well, 508 00:29:47,720 --> 00:29:50,760 Speaker 1: I'm still alive. I'm gonna keep doing my living stuff. Uh. 509 00:29:51,040 --> 00:29:55,920 Speaker 1: John Dalton died finally on July forty four. He was 510 00:29:56,040 --> 00:29:58,760 Speaker 1: really really beloved in Manchester by this point, and he 511 00:29:58,800 --> 00:30:00,800 Speaker 1: was given a public funeral all by the city on 512 00:30:00,840 --> 00:30:05,360 Speaker 1: August twelfth, eighteen forty four, and estimated forty people paid 513 00:30:05,440 --> 00:30:09,320 Speaker 1: their respects before Dalton was interred. The day after Dalton's death, 514 00:30:09,360 --> 00:30:13,480 Speaker 1: on July eighteen forty four, his wishes were carried out 515 00:30:13,960 --> 00:30:17,280 Speaker 1: his eyes were dissected. This was done by Dr Joseph 516 00:30:17,360 --> 00:30:21,080 Speaker 1: Bransom to determine whether this idea about having a blue 517 00:30:21,200 --> 00:30:24,480 Speaker 1: humor in his eye was correct. Of course it was not. 518 00:30:25,280 --> 00:30:28,720 Speaker 1: Ransom described what he found in Dalton's eye as quote 519 00:30:28,840 --> 00:30:32,920 Speaker 1: perfectly pellucid and some also sliced off a section of 520 00:30:32,960 --> 00:30:36,280 Speaker 1: the posterior pole of the eye and used it as 521 00:30:36,280 --> 00:30:38,920 Speaker 1: a lens to see if colors that were viewed through it, 522 00:30:39,040 --> 00:30:41,560 Speaker 1: especially red and green, took on a different hue, which 523 00:30:41,560 --> 00:30:45,000 Speaker 1: they did not. But Dalton's eyes were not discarded after that, 524 00:30:45,200 --> 00:30:48,120 Speaker 1: so for clarity he did the full dissection on one eye. 525 00:30:48,120 --> 00:30:50,720 Speaker 1: That little part he sliced off was from the second eye, 526 00:30:51,320 --> 00:30:55,240 Speaker 1: um so he had only taken the primary samples from one. 527 00:30:55,480 --> 00:30:58,800 Speaker 1: The other was mostly intact, and the remains of Dalton's 528 00:30:58,840 --> 00:31:00,680 Speaker 1: eyes were preserved and were even actually given to the 529 00:31:00,680 --> 00:31:04,640 Speaker 1: Manchester Literary and Philosophical Society. That was not the end 530 00:31:04,640 --> 00:31:08,160 Speaker 1: of their story. A hundred years after Dalton died in 531 00:31:09,600 --> 00:31:13,760 Speaker 1: a DNA analysis was conducted on his preserved eyes, and 532 00:31:13,800 --> 00:31:17,760 Speaker 1: this examination determined that he had due to anopia, conclusively 533 00:31:17,800 --> 00:31:21,120 Speaker 1: proving that he had red green color vision deficiency. Two 534 00:31:21,200 --> 00:31:25,080 Speaker 1: years after those findings were published in seven the eyes 535 00:31:25,080 --> 00:31:28,480 Speaker 1: were donated to the Science and Industry Museum in Manchester 536 00:31:28,880 --> 00:31:31,840 Speaker 1: and they remain in the collection there to this day. Yeah, 537 00:31:31,880 --> 00:31:35,560 Speaker 1: you can find pictures of him online. Uh. In the 538 00:31:35,600 --> 00:31:39,960 Speaker 1: eighteen seventies, German anatomis Max Schultz identified the rods and 539 00:31:40,000 --> 00:31:43,080 Speaker 1: cones of the retina and deduced that rods were dedicated 540 00:31:43,080 --> 00:31:46,640 Speaker 1: to night vision and cones to daylight vision. Then later 541 00:31:46,680 --> 00:31:49,880 Speaker 1: in the eighteen seventies, Wilhelm kun laid the groundwork for 542 00:31:49,920 --> 00:31:54,320 Speaker 1: a concept of photochemical basis for vision. In the nineties, 543 00:31:54,360 --> 00:31:59,960 Speaker 1: Spanish neuroscientists Santiago Ramonica how studied the retina and drew 544 00:32:00,080 --> 00:32:04,320 Speaker 1: detailed diagrams of the cells within it. How scientific drawings 545 00:32:04,360 --> 00:32:07,640 Speaker 1: are incredibly intricate and very beautiful, and they were part 546 00:32:07,680 --> 00:32:12,160 Speaker 1: of an art exhibit at n y U. Yeah. So 547 00:32:12,720 --> 00:32:15,440 Speaker 1: you know, all of the things that would have explained 548 00:32:15,480 --> 00:32:17,760 Speaker 1: to Dalton what was going on came a little too late. 549 00:32:18,200 --> 00:32:22,960 Speaker 1: There was also a cool discovery so fairly recently, a 550 00:32:23,000 --> 00:32:26,120 Speaker 1: new kind of photo receptor was discovered, the ganglion cell, 551 00:32:26,680 --> 00:32:28,920 Speaker 1: and that once again refined our knowledge of how the 552 00:32:29,000 --> 00:32:38,560 Speaker 1: human eye takes in and processes visual information. Always learning. UM, 553 00:32:38,600 --> 00:32:42,600 Speaker 1: I really really really love John dalton story, and I 554 00:32:42,680 --> 00:32:46,000 Speaker 1: love this part of it. Um. I knew a little 555 00:32:46,000 --> 00:32:49,360 Speaker 1: bit more about you know, his work in in establishing 556 00:32:49,400 --> 00:32:51,360 Speaker 1: the basis of a lot of the chemistry we use, 557 00:32:52,120 --> 00:32:54,600 Speaker 1: but I didn't. I had never read this paper before, 558 00:32:54,720 --> 00:33:02,080 Speaker 1: and I honestly it's the most fun reading. It's very sweet. 559 00:33:03,320 --> 00:33:07,920 Speaker 1: I will switch gears completely form our listener mail though 560 00:33:08,320 --> 00:33:12,920 Speaker 1: okay one I won't read his mail because it's pretty short, 561 00:33:12,960 --> 00:33:15,239 Speaker 1: but I'll sum it up. I wanted to say hi 562 00:33:15,400 --> 00:33:17,520 Speaker 1: to Todd who wrote us he was listening to our 563 00:33:17,560 --> 00:33:21,240 Speaker 1: transfusion episodes while he donated platelets. So thank you Todd 564 00:33:21,280 --> 00:33:23,560 Speaker 1: for donating platelets. We have had several people right in 565 00:33:23,640 --> 00:33:26,800 Speaker 1: to make sure that we uh let people know that 566 00:33:26,840 --> 00:33:29,840 Speaker 1: donating blood is very important and it is. So this 567 00:33:29,920 --> 00:33:32,480 Speaker 1: is your p s A again and again, thank you Todd. 568 00:33:32,520 --> 00:33:34,800 Speaker 1: But my actual email that I'm gonna read is from 569 00:33:34,880 --> 00:33:37,840 Speaker 1: our listener, Larissa. I think that's probably how she pronounces it. 570 00:33:38,120 --> 00:33:40,160 Speaker 1: Who writes Hi, Holley and Tracy. I've been a fan 571 00:33:40,240 --> 00:33:43,080 Speaker 1: since sixteen and I always look forward to new episodes 572 00:33:43,160 --> 00:33:45,800 Speaker 1: each week. It helps keep my brain limber while at 573 00:33:45,840 --> 00:33:48,080 Speaker 1: home with the kids during lockdown, which we are currently 574 00:33:48,120 --> 00:33:51,640 Speaker 1: experiencing here in Ontario. Recently, I have been thrilled to 575 00:33:51,680 --> 00:33:54,920 Speaker 1: make connections between your podcast in my library. I just 576 00:33:54,960 --> 00:33:58,040 Speaker 1: finished reading Scherie Demelin's Empire of Wild, which is a 577 00:33:58,120 --> 00:34:01,560 Speaker 1: novel set within the Matti community of Georgian Bay, Canada, 578 00:34:01,760 --> 00:34:04,840 Speaker 1: in which a rugarou plays a major part. The moment 579 00:34:04,880 --> 00:34:07,040 Speaker 1: of the novel that answered the niggling part of my 580 00:34:07,080 --> 00:34:09,720 Speaker 1: brain that said, Ruguru, Where have I heard that before? 581 00:34:10,040 --> 00:34:12,640 Speaker 1: Was when one of the characters leaves thirteen objects on 582 00:34:12,680 --> 00:34:15,640 Speaker 1: her porch to protect herself because the rugarou can only 583 00:34:15,680 --> 00:34:18,760 Speaker 1: count to twelve. I'm so curious about how the creature 584 00:34:18,800 --> 00:34:21,400 Speaker 1: became part of both culture. Surely the link must be 585 00:34:21,440 --> 00:34:24,000 Speaker 1: the French. This may have set off the great rugaru 586 00:34:24,040 --> 00:34:28,200 Speaker 1: investigation of one on my part, invest which is yes, 587 00:34:28,520 --> 00:34:30,560 Speaker 1: we mentioned in that episode, although we didn't go super 588 00:34:30,600 --> 00:34:34,439 Speaker 1: deep because there's not really documentation of it that Since 589 00:34:34,520 --> 00:34:38,719 Speaker 1: Ruguru is kind of a shift from Lugaru, which is 590 00:34:38,760 --> 00:34:43,000 Speaker 1: French for werewolf, it seems to have traveled over with 591 00:34:43,120 --> 00:34:48,640 Speaker 1: French colonists, uh, and French fur trappers kind of became 592 00:34:48,760 --> 00:34:51,759 Speaker 1: pretty standard in in that area in the north and 593 00:34:51,760 --> 00:34:57,160 Speaker 1: then migrated south into Louisiana. That is the best guess 594 00:34:57,200 --> 00:34:59,200 Speaker 1: how it traveled since we don't have, like I said, 595 00:34:59,239 --> 00:35:02,080 Speaker 1: hard documentation him. But I love that the Rugaru and 596 00:35:02,200 --> 00:35:05,640 Speaker 1: his inability to count beyond a dozen is still delighting 597 00:35:05,680 --> 00:35:07,759 Speaker 1: people and making us all laugh because we need it 598 00:35:07,880 --> 00:35:10,200 Speaker 1: right now. Uh. If you would like to write to us, 599 00:35:10,239 --> 00:35:13,200 Speaker 1: you can do so at History podcast at iHeart radio 600 00:35:13,239 --> 00:35:15,319 Speaker 1: dot com. You can also find us as Missed in 601 00:35:15,400 --> 00:35:18,600 Speaker 1: History everywhere on social media. If you have not subscribed 602 00:35:18,640 --> 00:35:20,399 Speaker 1: to the show, why not, You can do it right now. 603 00:35:20,440 --> 00:35:21,880 Speaker 1: It's super easy, and you can do that on the 604 00:35:21,880 --> 00:35:24,680 Speaker 1: I heart Radio app, at Apple podcasts, or wherever you 605 00:35:24,719 --> 00:35:32,200 Speaker 1: listen to your favorite podcasts. Stuff you Missed in History 606 00:35:32,239 --> 00:35:34,960 Speaker 1: Class is a production of I heart Radio. For more 607 00:35:35,040 --> 00:35:38,040 Speaker 1: podcasts from I heart Radio, visit the i heart Radio app, 608 00:35:38,160 --> 00:35:41,360 Speaker 1: Apple Podcasts or wherever you listen to your favorite shows,