The important phosphorus compounds in organisms are much more complex
than the simple salts, to which Nietzsche attributed such influence on
man's character. Long before he wrote, it was known that phosphoric acid
combines not only with inorganic bases to form salts, but with alcohols
to form esters. In the middle of the 19th century, Théophile Juste
Pelouze (1807-1867) extended this knowledge to an ester of glycerol.
This proved to be significant in several respects. Glycerol had been
shown by Michel Chevreul (1786-1889) as the substance in fats that is
released in the process of soap boiling, when the fatty acids are
converted into their salts. That it has the nature of an alcohol had
been demonstrated by Marcellin Berthelot. Instead of one "alcoholic"
hydroxyl group, OH, like ethanol (the alcohol of fermentation), or two
hydroxyl groups (like ethylene glycol), glycerol contains three such
groups. It was the only "natural" alcohol known at that time. That this
alcohol would combine with phosphoric acid could be predicted, but that
the ester, as obtained by Pelouze, still contained free acidic functions
and formed a water-soluble barium salt was a new experience.
[Illustration: Figure 12.--PAN FOR DIPPING MATCHSTICKS into phosphorus
paste, about 1870. The letters on the picture are: A, matches; B, water
bath; C, frame; D, plate; E, phosphorus paste; F, oven. The phosphorus
paste of Böttger, 1842, contained 10 phosphorus, 25 antimony sulfide,
12.5 manganese dioxide, 15 gelatin. According to Figuier (page 579), R.
Wagner substituted lead dioxide for the manganese dioxide. (From
FIGUIER, volume 3, 1874, page 576.)]