INTRODUCTION. 7 
about finding it out for himself. He knew that 
Brandt, who died shortly afterwards, had devoted 
most of his life to experiments on urine, and he 
felt convinced that phosphorus must have been 
obtained from that liquid. After many and varied 
experiments, quite unsuccessful, Kunkel at last 
obtained (in the year 1674) the substance he sought 
after so long and so obstinately.* 
In the year 1675, another chemist, Baudoin, 
prepared a new “phosphorus,” or shining sub- 
stance, by calcining nitrate of lime. Since then, 
many substances which shine in the dark after ex- 
posure to the sun, have been discovered. One of 
the most remarkable, perhaps, is ‘‘Canton’s Phos- 
phorus,” or sulphuret of calctum, obtained accord- 
ing to the author just named “ by heating a mix- 
ture of three parts of sifted calcined oyster-shells 
with one part of sulphur to an intense heat for one 
hour.” It can also be prepared by calcining 
plaster of Paris with common charcoal. 
The peculiar and sometimes extremely vivid 
phosphorescence of the sea was known in anti- 
quity. Pliny speaks of it, and of the phosphores- 
cence of certain Medusee. But it was not till long 
afterwards that the cause of this wonderful phe- 
* Some authors state that phosphorus was discovered in Eng- 
land, about the same time, by Robert Boyle. In 1769, Gahn, 
the celebrated Swedish mineralogist, discovered it in bones, and 
published, with the illustrious Scheele, a new process for extract- 
ing it, which is similar to the one practised at the present day. 
