ed on a discovery made
by a shoemaker, Vicenzo Casciarolo, on a mountain-side near Bologna in
1630.[2] Was the substance new which Brand showed to his friends? Johann
Gottfried Leonhardi quotes a book of 1689 in which the author, Kletwich,
claims that this phosphorus had already been known to Fernelius, the
court physician of King Henri II of France (1154-1189).[3] To the same
period belongs the "Ordinatio Alchid Bechil Saraceni philosophi," in
which Ferdinand Hoefer found a distillation of urine with clay and
carbonaceous material described, and the resulting product named
escarbuncle.[4] It would be worth looking for this source; although
Bechil would still remain an entirely unsuccessful predecessor, it does
seem strange that in all the distillations of arbitrary mixtures, the
conditions should never before 1669 have been right for the formation
and the observation of phosphorus.

[Illustration: Figure 1.--THE ALCHEMIST DISCOVERS PHOSPHORUS. A painting
by Joseph Wright (1734-1779) of Derby, England.]

For Brand's contemporaries at least, the discovery was new and exciting.
The philosopher Gottfried Wilhelm von Leibniz (1646-1716) considered it
important enough to devote some of his time (between his work as
librarian in Hanover and Wolfenbuettel, his efforts to reunite the
Protestant and the Catholic churches, and his duties as Privy Councellor
in what we would call a Department of Justice) to a history of
phosphorus. This friend of Huygens and Boyle tried to prove that Kunckel
was not justified in claiming the discovery for himself.[5] Since then,
it has been shown that Johann Kunckel (1630-1703) actually worked out
the method which neither Brand nor his friend Kraft wanted to disclose.
Boyle also developed a method independently, published it, and
instructed Gottfried Hankwitz in the technique. Later on, Jean Hellot
(1685-1765) gave a meticulous description of the details and a long
survey of the literature.[6]

[Illustration: Figure 2.--GALLEY-OVEN, 1869. The picture is a cross
section through the front of the oven showing one of the 36 retorts, the
receivers for the distillate, and the space in the upper story used for
evaporating the mixture of acid solution of calcium phosphate and coal.
(According to ANSELME PAYEN, _Precis de Chimie industrielle_, Paris,
1849; reproduced from HUGO FLECK, _Die Fabrikation chemischer Produkte
aus thierischen Abfaellen_, Vieweg, Braunschweig, 1862, page 80 of volume
2, 2nd gro