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The Art of Manliness Continued JOBS for TEAMS | 16 www.jobsfor teams.com the ancient Greeks and Romans. The first record of it comes from Pliny the Elder in the first century AD, who mentioned using the milk of the tithymalus plant as an invisible ink in his Natural His- tory. Invisible ink continued to be used during the Renaissance; statesmen used it in their letters, and Ovid references the practice in his Art of Love. Giovanni Battista della Porta, an Italian polymath, developed a formula for invisible ink that consisted of an ounce of alum and a pint of vinegar. Once painted on the shell of a hard-boiled egg, it would seep through and transfer the message onto the egg's albumen. The writing could only be seen once the egg was peeled. The Revolution During the Revolutionary War, both the British and the Americans used invisible ink. The British used both organic fluids and common sympathetic inks. Major John Andre, the chief British intelligence officer, had agents put a letter in the corner of their correspondence to inform the recipi- ent as to how the hidden secret message could be developed; for example, an "F" was placed in the corner of letters that could be revealed by fire, an "A" for those that needed the application of an acid. But George Washington wanted some- thing more, an ink that could only be revealed by a unique, specially formulated reagent. Sir James Jay answered the gen- eral's call. Jay, brother of American patriot John Jay and a physician that dabbled in chemistry, created a "sympathetic stain," which he supplied to Washington. Wash- ington would then pass it on to the Conti- nental Army's spymaster, Major Benjamin Tallmadge who in turn provided it to the members of the famous Culper Spy Ring: Abraham Woodhull and Robert Townsend. To avoid suspicion, Washington instructed his spies to write seemingly banal letters between the lines of their secret mes- sages, or to inscribe them "on the blank leaves of a pamphlet. . . a common pocket book, or on the blank leaves at each end of registers, almanacs, or any publication or book of small value." World War I In contrast to the billion-dollar-budget- ed intelligence agencies of today, when America entered the First World War, the CIA did not exist, and the FBI was barely 15 years old. The Office of Naval Intel- ligence coordinated the gathering of the country's intelligence. In a pamphlet included in the recently unclassified documents mentioned in the introduction, we can see that chemical inks were employed during this time, but basics like lemon juice and milk were still in use as well. While the Americans were falling back on old favorites, the Germans were at the leading edge of invisible ink development. At the beginning of the war, the Germans used inks made from head- ache and fever remedies and laxatives; these were handy as they could be passed off as common medicines. But when the Allies caught on, they were forced to develop inks outside those based on com- mon household items. They utilized inks made from iron sulfate, copper sulfate, and cobalt salts, and employed reagents of sodium carbonate, ammonia fumes, and potassium ferroscyanide. Both sides worked to find a universal reagent that could develop every invisible ink, no matter its chemical composition. The Allies struck upon a solution when they discovered that iodine vapor would turn all invisible inks brown. It worked not by chemical reaction, but by reveal- ing where the the paper's fibers had been altered with moisture. JobsForTeams0614_manliness.indd 2 5/6/14 4:29 PM