Weighed the Earth but Thought He Had Captured Phlogiston in a Bottle

Black was a gifted teacher and his classic text Lectures on the Elements of Chemistry was published posthumously (Edinburgh, 1803 Philadelphia, 1807). He undoubtedly delighted and puzzled audiences by pouring fixed air (which is denser than common air) out of a glass to extinguish a candle flame. Black also showed that the same gas was generated by fermentation as well as by respiration since these emissions also turned lime water milky and were therefore CO2. 

CAVENDISH WEIGHED THE EARTH BUT THOUGHT HE HAD CAPTURED PHLOGISTON IN A BOTTLE 

Although we modern chemists go to some lengths to let the public know that we play tennis, like fast cars and stylish clothes, and are down-to-earth social-mixer types, we must admit that our passion for smelly, smoky mixtures will likely get us booted from most respectable country clubs. Henry Cavendish (1731-1810) was definitely an unworldly type. He lived with his father until the latter died in 1783, did not marry, communicated with his housekeeper using daily notes, and dressed in shabby, outdated clothing despite Inheriting a fortune when he was 40. The French physicist Jean-Baptiste Biot described him as the richest of all learned men, and very likely also the most learned of all the rich.  

In our modem era when university tenure decisions are sometimes based upon the sheer poundage of publications, it is interesting to note that Cavendish published 18 papers in the Philosophical Transactions of the Royal Society (and no books). He left many unpublished works and unstylishly referred to them In his published works. 

FIGURE 182. Apparatus used by Henry Cavendish to discover hydrogen and manipulate gases [Philosophical Transactions of the Royal Society (London), LVI 141, 1766]. He thought that he had isolated phlogiston itself. 

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