320 VENOMS 
the formula of which, according to the latter author, is said to be 
CUA205, 
Bufotalin is readily soluble in alcohol, chloroform, acetone, 
acetate of ethyl, and acetic acid. When water is added to a 
solution of it in alcohol it is precipitated, giving a white emulsion, 
which has a very bitter taste. 
From the aqueous extract whence the bufotalin has been 
separated, it is possible to separate a second poison, which acts 
on the nervous system and causes paralysis. In order to obtain 
it in a pure state, the extract is treated with alcohol at 96° C., 
filtered and distilled; the residue dissolved in water is defæcated 
with subacetate of lead and sulphuretted hydrogen. The solution 
thus obtained is successively exhausted with chloroform to extract 
the cardiac poison, and with ether, which removes almost the 
whole of the acetic acid. The second neurotoxic principle, called 
bufotenin, remains in the residue of the solution after being 
evaporated im vacuo. 
Toad-venom, therefore, contains two principal toxic substances : 
bufotalin, which is of a resinoid nature, soluble in alcohol, but 
scarcely soluble in water, and is the cardiac poison; and bufotenin, 
which is readily soluble in those two solvents, and is the newro- 
toxic poison. 
Préscher, on the other hand, has extracted from the skins of 
toads a hemolytic substance, termed by him phrynolysin, which 
possesses all the properties of a true toxin and is not dialysable. 
It is obtained by pounding the skins with glass powder in physio- 
logical serum. 
Phrynolysin dissolves the red corpuscles of the sheep very 
rapidly, and (in order of sensitiveness) those of the goat, rabbit, 
dog, ox, fowl, and guinea-pig. The red corpuscles of the pigeon, 
frog, and toad are scarcely affected. When heated at 56° C. it 
1“ Rapports des venins avec la biologie générale,” Revue générale des 
Sciences, December 30, 1903. 
