with sand under hot
water, cooled, drained, and filled into the retort. The outlet of the
retort, at least 6 cm. in diameter, is partially immersed in the water
contained in the bucket. A small dish, made from lead, with an iron
handle, receives the distilled phosphorus. (From HUGO FLECK, _Die
Fabrikation chemischer Produkte ..._ page 90.)]

The most exciting early use, however, was in medicine. It is not
surprising that such a use was sought at that time. Any new material
immediately became the hope of ailing mankind--and of striving
inventors.[16] Phosphorus was prescribed, in liniments with fatty oils
or as solution in alcohol and ether, for external and internal
application. A certain Dr. Kramer found it efficient against epilepsy
and melancholia (1730). A Professor Hartmann recommended it against
cramps.[17] However, in the growing production of phosphorus for
matches, the workers experienced the poisonous effects. In the plant of
Black and Bell at Stratford, this was prevented by inhaling turpentine.
Experiments on dogs were carried out to show that poisoning by
phosphorus could be remedied through oil of turpentine.[18]

[Illustration: Figure 4.--APPARATUS FOR CONVERTING WHITE PHOSPHORUS into
the red allotropic form, 1851. Redistilled phosphorus is heated in the
glass or porcelain vessel (g) which is surrounded by a sandbath (e) and
a metal bath (b). Vessel (j) is filled with mercury and water; together
with valve (k), it serves as a safety device. The alcohol lamp (l) keeps
the tube warm against clogging by solidified vapors. Because of hydrogen
phosphides, the operation, carried out at 260 deg. C., had to be watched
very carefully. (According to Arthur Albright, 1851; reproduced from
HUGO FLECK, _Die Fabrikation chemischer Produkte ..._, page 112.)]

Chemical Constitution of Phosphoric Acids

In a long article on phosphorus, Edmond Willm wrote in 1876: "For a
century, urine was the only source from which phosphorus was obtained.
After Gahn, in 1769, recognized the presence of phosphoric acid in
bones, Scheele indicated the procedure for making phosphorus from
them."[19] Actually, Gahn used at first hartshorn (_Cornu cervi
ustum_), and Scheele doubted, until he checked it himself, that his
esteemed friend was right. A few years later, Scheele corrected Gahn's
assumption that the _sal microcosmicum_ was an ammonia salt; instead, it
is "a tertiary neutral salt, consisting of _alkali minerali fixo_ (i.e.