RESEARCHES ON NARCOTINE, ETC. 
137 
and transparent for several hours ; it then becomes white 
and hard, beginning at the surface, but so slowly that a 
transparent soft nucleus may be found after several days in 
large fused masses, resembling in this respect arsenious 
acid. It has now become insoluble in water and alcohol, 
nay even in dilute alkalies. If water be added to it while 
it is still clear and amorphous, it becomes milk-white, and 
on boiling is converted into a white earthy mass, of which 
extremely little dissolves, and which again separates on 
cooling in white amorphous flakes. The melted insoluble 
acid was found on analysis to possess the same quantita- 
tive composition as the crystallized. The explanation of 
this isomerism will appear subsequently. 
The analysis of opianic acid, and of its salts of silver and 
lead afforded for the crystallized acid the formula C 20 H 8 
9 +HO; in the salts the water is replaced by 1 atom of 
base. The atomic weight of the anhydrous acid is 2502.23. 
Opianic acid forms with baryt.es. oxide of lead and oxide 
of silver, readily-soluble salts, which crystallize well, and 
part with water of crystallization by exposure of heat. 
2. Opianic Ether. — This body could not be obtained 
by acting with muriatic acid gas on a solution of opianic 
acid in alcohol, but it is readily obtained by employing sul- 
phurous instead of muriatic acid. It crystallizes on evapo- 
ration of the concentrated solution in minute colorless prisms, 
united into bundles and spheres. It possesses no odor and 
scarcely any taste ; it is insoluble in cold water ; when heated 
with it, it melts at about 212° to a clear heavy liquid, which 
on cooling solidifies to a white radiately-crystalline mass, 
with considerable contraction ; it sublimes. Boiled for some 
length of time in water, it gradually dissolves, being con- 
verted into alcohol and opianic acid ; this is very rapidly ef- 
fected by caustic potash. The analysis confirmed its being 
of the oxide of ethyle =C 4 H 5 + C 20 H 8 G 9 . 
3. Opiammon. — This is a product of the metamorphosis 
of the opianate of ammonia j it forms on the evaporation of 
