RESEARCHES ON NARCOTINE, ETC. 
139 
lution has a very peculiar bitter taste, and leaves behind for 
a long time a peculiar sweetish after-taste. Carbonate of 
lead and barytes dissolve in the liquid, and form beautiful 
crystalline salts, characterized by their lustre. It reduces 
selenium from selenious acid, and gold from perchloride of 
gold. 
When the solution of opianic acid in sulphurous acid is 
evaporated at a gentle heat, the new compound is left as a 
crystalline transparent mass. It is perfectly free from smell. 
When treated with water it becomes milk-white, and ac- 
quires a strong odor of sulphurous acid. The separated 
white substance is unaltered opianic acid: this decomposi- 
tion however is only partial. 
The analyses of the lead and barytes salts have shown 
that a composition of this body may be expressed by the 
formula C 20 H 6 O 7 2S0 2 -f HO. The atom of water re- 
presents the bases in the salts. The author will subse- 
quently return to the consideration of its peculiar composi- 
tion. 
6. Sulphopianic Acid. — This is an organic compound 
with sulphur, which is generated by the action of sulphu- 
retted hydrogen gas on opianic acid, dissolved in water at 
a temperature of 15S°. A gradually increasing turbidness 
results, which appears like precipitated sulphur; the body 
however which separates, and into which the whole of the 
opianic acid is converted, is the new compound. The gas 
must be passed through several days before the action is 
complete. The sulphopianic acid separates as a yellowish 
powder. On heating the liquid to boiling, the precipitate 
melts to a pale yellow clear oil, which sinks to the bottom 
and solidifies on cooling. 
In this state the sulphopianic forms an amorphous, trans- 
parent, sulphur-yellow mass; below 212° it becomes soft, 
and at that temperature entirely liquid; heated more 
strongly, it is decomposed, giving off voluminous sulphur- 
yellow vapors, which condense into minute yellow acicular 
