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RESEARCHES ON NARCOTINE, ETC. 
crystals, which are readily soluble in alcohol. It burns 
with flame and with the odor of sulphurous acid. It is 
entirely soluble in alcohol, with a yellow color: if it had 
been melted, it is again obtained, even on spontaneous eva- 
poration, in an amorphous state ; but if the temperature had 
been so arranged at its formation that the precipitate could 
not become soft, it separates from the alcohol in minute 
yellow prisms; it undergoes therefore a similar metamor- 
phosis at its melting point as the opianic acid. It is dissolved 
by alkalies with a yellow color, from which it is precipita- 
ted by acids in the form of a yellow emulsion, and without 
any disengagement of sulphuretted hydrogen. After some 
time however these solutions contain an alkaline sulphuret. 
In their unaltered state they afford with salts of lead and 
silver brownish-yellow precipitates, which are converted at 
a boiling heat into black sulphurets. 
Sulphopianic acid is constituted according to the formula 
C 2 oH 8 7 S 2 . It may therefore be regarded as hydrated 
opianic acid, in which 2 atoms of oxygen have been re- 
placed by 2 atoms of sulphur ; its formation is therefore 
quite simple. 
The existence and composition of these bodies derived 
from opianic acid appear to afford some explanation respect- 
ing the true nature of this acid. The elements of 2 atoms 
of water are evidently removed from its composition by the 
influence of sulphurous acid and sulphuretted hydrogen, 
equivalent quantities of which take their place. To the 
author it appears most simple to admit, that besides the 
atom of water substitutable by bases, these 2 atoms of water 
are contained likewise as such in the opianic acid in a state 
of combination, in which they cannot be separated by bases, 
just as little as the organic body contained in benzoe-sul- 
phuric acid separates from the sulphuric acid on its union 
with bases. The author regards opianic acid as a conjuga- 
ted acid, the copula in which consists of 2 atoms of water, 
