1 00:00:00,120 --> 00:00:01,960 Speaker 1: This Day in History Class as a production of I 2 00:00:02,040 --> 00:00:09,080 Speaker 1: Heart Radio. Hello and Welcome to This Day in History Class, 3 00:00:09,119 --> 00:00:12,200 Speaker 1: a show that reveals a little bit more about history 4 00:00:12,600 --> 00:00:17,400 Speaker 1: every day time Gabe Lousier and in this episode, we're 5 00:00:17,400 --> 00:00:21,840 Speaker 1: talking about a breakthrough form of espionage from the Revolutionary War, 6 00:00:22,440 --> 00:00:26,119 Speaker 1: a new kind of invisible ink than only one side 7 00:00:26,280 --> 00:00:36,040 Speaker 1: knew how to use. The day was November nine, seventeen 8 00:00:36,240 --> 00:00:42,280 Speaker 1: seventy five. Physician and amateur chemist James j invented a 9 00:00:42,320 --> 00:00:45,320 Speaker 1: new kind of invisible ink, which was later put to 10 00:00:45,440 --> 00:00:49,960 Speaker 1: use in the American War of Independence. From the seventeen 11 00:00:50,040 --> 00:00:53,599 Speaker 1: fifties until the start of the war, ja had studied 12 00:00:53,640 --> 00:00:57,400 Speaker 1: and practiced medicine in Great Britain. When the war broke 13 00:00:57,440 --> 00:01:00,840 Speaker 1: out in the colonies, he used his new invisible ink 14 00:01:01,120 --> 00:01:05,679 Speaker 1: to correspond with John Jay, an American patriot, and his 15 00:01:05,840 --> 00:01:11,360 Speaker 1: more famous younger brother, eventually with James Blessing. John Jay 16 00:01:11,600 --> 00:01:15,920 Speaker 1: offered his brother's inc to General George Washington, who immediately 17 00:01:15,959 --> 00:01:19,040 Speaker 1: put it to use In the famous Culper Spy ring 18 00:01:20,080 --> 00:01:25,600 Speaker 1: during the Revolutionary War, both combatants used invisible ink. British 19 00:01:25,640 --> 00:01:29,840 Speaker 1: soldiers would dip their quills in something acidic like lime juice, 20 00:01:30,000 --> 00:01:34,200 Speaker 1: lemon juice or vinegar, and then write secret messages between 21 00:01:34,280 --> 00:01:39,160 Speaker 1: the lines of seemingly mundane letters. The hidden writing would 22 00:01:39,200 --> 00:01:42,679 Speaker 1: only appear if the recipient did one of two things, 23 00:01:43,200 --> 00:01:46,160 Speaker 1: either hold the letter over the flame of a candle 24 00:01:46,640 --> 00:01:49,880 Speaker 1: or treat the paper with a chemical substance such as 25 00:01:49,920 --> 00:01:55,160 Speaker 1: sodium carbonate. These methods worked because the acidic ink would 26 00:01:55,240 --> 00:01:58,360 Speaker 1: weaken the fibers of the paper, so that when heat 27 00:01:58,600 --> 00:02:02,840 Speaker 1: or acid was applied, the weekend fibers would turn brown 28 00:02:03,040 --> 00:02:07,200 Speaker 1: faster than the fibers that hadn't touched the ink. The 29 00:02:07,280 --> 00:02:10,600 Speaker 1: main problem with these types of invisible ink was that 30 00:02:10,760 --> 00:02:13,959 Speaker 1: both sides knew how to use them. If a letter 31 00:02:14,080 --> 00:02:17,600 Speaker 1: was intercepted and the enemies suspected it might contain a 32 00:02:17,680 --> 00:02:21,720 Speaker 1: hidden message, they knew exactly how to check. In fact, 33 00:02:22,000 --> 00:02:25,720 Speaker 1: one British intelligence officer made it even easier to tell. 34 00:02:26,440 --> 00:02:29,320 Speaker 1: He instructed his agents to mark the corner of their 35 00:02:29,360 --> 00:02:33,840 Speaker 1: correspondence with either an A or an F. This told 36 00:02:33,880 --> 00:02:38,120 Speaker 1: the recipient or the interceptor exactly how to make the 37 00:02:38,200 --> 00:02:43,519 Speaker 1: secret message appear with acid or with fire. James j 38 00:02:43,880 --> 00:02:48,320 Speaker 1: recognized that most invisible ink formulas had become too common 39 00:02:48,400 --> 00:02:52,160 Speaker 1: to be effective to combat the problem. He developed his 40 00:02:52,240 --> 00:02:55,840 Speaker 1: own unique recipe for ink, one that could only be 41 00:02:55,960 --> 00:03:01,320 Speaker 1: activated by a specific corresponding re agent. It didn't matter 42 00:03:01,440 --> 00:03:05,480 Speaker 1: how much heat or sodium carbonate you tried. Without knowing 43 00:03:05,600 --> 00:03:11,359 Speaker 1: Jay's exact formula, his invisible ink would stay invisible. When 44 00:03:11,360 --> 00:03:14,760 Speaker 1: George Washington heard of this new form of invisible ink, 45 00:03:15,080 --> 00:03:18,120 Speaker 1: he couldn't contain his excitement. He wrote a letter to 46 00:03:18,200 --> 00:03:22,600 Speaker 1: a lawyer and statesman named Elias Boutineau, singing the praises 47 00:03:22,639 --> 00:03:29,040 Speaker 1: of what he referred to as sympathetic stain. Washington giddily wrote, quote, 48 00:03:29,480 --> 00:03:32,680 Speaker 1: it is in my power I believe to procure a 49 00:03:32,720 --> 00:03:36,560 Speaker 1: liquid which nothing but a counter liquor rubbed over the 50 00:03:36,560 --> 00:03:42,640 Speaker 1: paper afterwards, can make legible fire, which will bring out lime, juice, milk, 51 00:03:42,800 --> 00:03:45,760 Speaker 1: and other things of this kind. To light has no 52 00:03:45,880 --> 00:03:50,040 Speaker 1: effect on it. A letter upon trivial matters of business, 53 00:03:50,320 --> 00:03:54,800 Speaker 1: written in common ink may be fitted with important intelligence 54 00:03:54,880 --> 00:04:00,640 Speaker 1: which cannot be discovered without the counterpart. Shortly after, James 55 00:04:00,760 --> 00:04:04,680 Speaker 1: ja began exporting small quantities of his invisible ink to 56 00:04:04,840 --> 00:04:11,000 Speaker 1: Washington and to the Continental Army Spy Master Major Benjamin Talmidge. 57 00:04:11,480 --> 00:04:14,200 Speaker 1: He in the General would then pass the ink along 58 00:04:14,320 --> 00:04:18,039 Speaker 1: to their secret agents in British occupied New York City. 59 00:04:18,160 --> 00:04:21,359 Speaker 1: They encouraged the agents to write their hidden messages in 60 00:04:21,400 --> 00:04:24,880 Speaker 1: the blank pages of books and pamphlets in order to 61 00:04:24,880 --> 00:04:28,800 Speaker 1: make them less suspicious. There was never as much of 62 00:04:28,960 --> 00:04:31,919 Speaker 1: Jay's ink as they would have liked, but the amount 63 00:04:31,960 --> 00:04:36,600 Speaker 1: they had, alongside their aliases and various forms of code 64 00:04:36,600 --> 00:04:39,560 Speaker 1: writing was enough to get them all the way through 65 00:04:39,600 --> 00:04:44,240 Speaker 1: the war without being caught. So what exactly was in 66 00:04:44,440 --> 00:04:49,440 Speaker 1: James Jay's mysterious white ink, or the medicine as Washington 67 00:04:49,480 --> 00:04:53,440 Speaker 1: would later refer to it in letters? Jay never revealed 68 00:04:53,480 --> 00:04:57,440 Speaker 1: the chemical composition of his formula, after all, writing it 69 00:04:57,440 --> 00:05:00,520 Speaker 1: down would have increased the risk of an outsider figuring 70 00:05:00,560 --> 00:05:04,400 Speaker 1: out how to use it. However, in the nineteen thirties, 71 00:05:04,880 --> 00:05:10,360 Speaker 1: doctor Lodwick Bendickson performed ultra violet and infrared tests on 72 00:05:10,520 --> 00:05:15,599 Speaker 1: letters written using Jay's invisible ink. The analysis revealed it 73 00:05:15,640 --> 00:05:19,080 Speaker 1: to be a solution made from the tannic acid of 74 00:05:19,240 --> 00:05:23,320 Speaker 1: gal nuts. What's a gal nut? It's not a nut, 75 00:05:23,640 --> 00:05:28,159 Speaker 1: but essentially a wooden cocoon. When a wasp laze its 76 00:05:28,200 --> 00:05:31,039 Speaker 1: eggs on the branches of an oak tree, the tree 77 00:05:31,160 --> 00:05:35,080 Speaker 1: defends itself by in tumbing the eggs within a big 78 00:05:35,120 --> 00:05:38,880 Speaker 1: woody growth known as a gal nut. As for the 79 00:05:39,000 --> 00:05:43,559 Speaker 1: substance used to reveal Jay's invisible ink, the test showed 80 00:05:43,600 --> 00:05:47,479 Speaker 1: it to be ferris sulfate, a soil additive used to 81 00:05:47,560 --> 00:05:51,719 Speaker 1: lower the pH of soil. Kudos to James J. For 82 00:05:51,839 --> 00:05:54,960 Speaker 1: coming up with that pairing. No way we're the British 83 00:05:55,040 --> 00:05:59,280 Speaker 1: going to crack that one. Jay's invisible ink help deliver 84 00:05:59,480 --> 00:06:04,200 Speaker 1: valuable strategic information to Washington and his allies, but the 85 00:06:04,240 --> 00:06:08,080 Speaker 1: inventor was never paid for his contribution to the war effort. 86 00:06:08,880 --> 00:06:12,240 Speaker 1: In eighteen oh eight, long after the war had been won, 87 00:06:12,800 --> 00:06:17,400 Speaker 1: Jay appealed for payment to President Thomas Jefferson and to Congress. 88 00:06:17,880 --> 00:06:22,080 Speaker 1: He requested twenty thousand dollars in recognition of his services, 89 00:06:22,480 --> 00:06:26,240 Speaker 1: claiming that his ink formula had proven invaluable and would 90 00:06:26,320 --> 00:06:30,200 Speaker 1: surely be of even more use in the future. Congress 91 00:06:30,360 --> 00:06:34,159 Speaker 1: was split on the matter. Some felt Jay was owed 92 00:06:34,200 --> 00:06:37,919 Speaker 1: the money, while others said it was quote absurd to 93 00:06:38,000 --> 00:06:40,640 Speaker 1: vote away money for a thing they did not and 94 00:06:40,720 --> 00:06:45,600 Speaker 1: could not understand. In the end, Congress sided with Jay, 95 00:06:45,640 --> 00:06:49,280 Speaker 1: declaring quote that it shall be lawful for the President 96 00:06:49,320 --> 00:06:52,320 Speaker 1: of the United States to obtain by purchase at a 97 00:06:52,320 --> 00:06:56,279 Speaker 1: reasonable price, the exclusive right on behalf of the public 98 00:06:56,720 --> 00:07:00,760 Speaker 1: of the system invented by Sir James J. As submitted 99 00:07:00,800 --> 00:07:04,479 Speaker 1: by him to the Executive Department of Government, provided in 100 00:07:04,520 --> 00:07:07,240 Speaker 1: the opinion of the President it will be of public 101 00:07:07,360 --> 00:07:11,840 Speaker 1: utility and importance to possess the same. In other words, 102 00:07:12,080 --> 00:07:15,720 Speaker 1: if President Jefferson wanted to pay James J. For their 103 00:07:15,800 --> 00:07:19,440 Speaker 1: rights to his invisible ink, Congress would have no objection. 104 00:07:20,240 --> 00:07:24,600 Speaker 1: But apparently that's not something Jefferson wanted to do. The 105 00:07:24,680 --> 00:07:28,800 Speaker 1: subject was broached again in eighteen thirteen, but the Senate 106 00:07:28,920 --> 00:07:33,600 Speaker 1: voted down the measure. James J. Died two years later, 107 00:07:34,080 --> 00:07:38,760 Speaker 1: never compensated for his efforts. His contributions to the nation 108 00:07:38,880 --> 00:07:46,000 Speaker 1: were lasting, but appreciation for them disappeared fast. I'm Gaye 109 00:07:46,040 --> 00:07:49,440 Speaker 1: Lousier and hopefully you now know a little more about 110 00:07:49,480 --> 00:07:53,320 Speaker 1: history today than you did yesterday. If you liked what 111 00:07:53,400 --> 00:07:57,600 Speaker 1: you heard, consider following us on Twitter, Facebook and Instagram 112 00:07:57,640 --> 00:08:01,120 Speaker 1: at t d i HC Show, and if you have 113 00:08:01,200 --> 00:08:04,360 Speaker 1: any comments or suggestions you can send them my way 114 00:08:04,560 --> 00:08:08,559 Speaker 1: at this day at I heeart media dot com. Thanks 115 00:08:08,560 --> 00:08:11,400 Speaker 1: to Chandler Mays for producing the show, and thank you 116 00:08:11,440 --> 00:08:14,600 Speaker 1: for listening I'll see you back here again tomorrow for 117 00:08:14,680 --> 00:08:27,320 Speaker 1: another day in history class. For more podcasts from I 118 00:08:27,360 --> 00:08:30,160 Speaker 1: heart Radio, visit the iHeart Radio app, Apple Podcasts, or 119 00:08:30,200 --> 00:08:31,800 Speaker 1: wherever you listen to your favorite shows.