pipe Re = 367 
thou ght oe to t tl as the e third 
200ks, we b ive us no caution. 
e po fyi ‘proper toanention that the spnphatane§ was, i 
this coe, prepared from a recipe furnished to me by Dr. 
Hare ;. it was as penta ‘Take lampblack three, calcin di 
alum four, and pearlashes eight parts—mix them thoroughly, 
and heat them, well in an iron. tube, to a_ bright cherry. red fos 
This ¢ yrophorus ed gone “When. ‘sali reparedand 
oured out upon a glass te and especially os lg aty 2} 
upon, it kindles with a series of small explosions, a little like 
those produced by throwing potassium upon water.. There 
is even some danger to the face and eyes from the number 
and rapid succession of these little explosions, and one is for- 
cibly impressed with the idea that they must be owing to pot- 
assium. . Since che discovery of this brilliant substance, there 
has been litde pasion that it is developed in greater or 
small s, during the formation of pyrophorus. The 
e cnt adapted to the production of 
ture a = x antity of the : 
it is now carrie is ses mas adept 
su gacible <0 of ———. and the liberated potas and 
potassuretted hydrogen burn with a brilliant deme’ anal the 
preg of satay, caustic alkali are extremely conspicu- 
Indeed it has long been known that charcoal will, by 
wee ignition, evolve potassium from potash. Curadeau 
first called our attention to this fact, and more recently Pro- 
fessor Brunner has shown that this process, skilfully con- 
ducted, is even preferable to any other 
[See Bib. Univ. Jan. 1823, ap in this Jornal, aid 
VU. p. 379. ] 
