Ben Franklin—Diplomate Extraordinaire

FIGURE 207. Portrait of Benjamin Franklin in the Ouevres De M. Franklin, Paris, 1773. The poem is translated in footnote 2 of this essay. (This book belonged to Dr. Werner Heisenberg, courtesy of his son Professor Jochen Heisenberg.) 

FIGURE 208. Madame Lavoisier was instructed in painting by the famous artist Jacques Louis David. This is a photo of the oil portrait she painted of her close friend Benjamin Franklin. See color plates. (Courtesy of a relative of Benjamin Franklin.) 

Neutral as he was on phlogiston, Franklin nonetheless made some highly original and insightful chemical speculations. One of the most fascinating is his statement of the conservation of matter in a 1752 letter composed when Lavoisier was but nine years old  

The action of fire only separates the particles of matter, it does not annihilate them. Water, by heat raised in vapour, returns to the earth in rain and if we collect all the particles of burning matter that go off in smoke, perhaps they might, with the ashes, weigh as much as the body before it was fired And if we could put them in the same position with regard to each other, the mass would be the same as before, and might be burnt over again. 

Although the law of conservation matter is strongly and quite properly associated with Lavoisier, its chemical consequences were stated explicitly at least a century earlier and, indeed, the concept dates back to antiquity. Nonetheless, Franklin s views on this matter are not widely known and his statement even suggests a specific experiment to verify the law. Franklin also reports witnessing the flammability of swamp gas (methane), in New Jersey, no less, over a decade be- 

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