CRYSTALLINE CONSTITUENTS OF OPIUM. 209 
This leads to the formula C,, H, (NO,) O,, which is exactly the same as that 
of the substance described by Coverze under the name of hyponitromeconic acid. 
This substance, according to CovEerBE, is an acid capable of combining with the 
alkalies, and yielding precipitates with the salts of iron and copper. It occurs in 
long yellow needles, gives yellow solutions with water and alcohol, but not with 
ether, and dissolves in the alkalies with a dark yellow, almost red colour, and is 
precipitated by acids. It is said to melt at 302°. These characiers, though dif- 
fering very remarkably from those of nitropianyl, approximate so closely in other 
respects that there can be no doubt about the identity of the two substances, al- 
though the discrepancies are somewhat puzzling. Some of them may, no doubt, 
be explained on the supposition that CovERBE’s substance was impure; but others 
searcely admit of any such explanation. This particularly applies to his descrip- 
tion of the mode in which it was obtained. He says that nitric acid is to be boiled 
with meconine, and the fluid evaporated to complete expulsion of the acid, and the 
residue, on treatment with water, gives hyponitromeconic acid. I found, on the 
contrary, that the residue, which represented only a small quantity of the opiany] 
or meconine employed, was highly soluble in water, and the solution gave, on 
evaporation, an amorphous mass which dissolved in almost all proportions in alco- 
hol and ether. In one instance only in which this process was tried, a small 
quantity of a crystalline matter was obtained. The soluble substance was not 
examined, as its properties were not such as to neat of easy purification. It is 
probably a further substitution product. 
Action of Chlorine on Opianyl. 
When a current of chlorine is passed into a cold saturated solution of opianyl 
in water, crystals soon begin to make their appearance, and gradually fill the 
whole fluid. In preparing this substance in large quantity, it is convenient to 
employ a warm solution, so that the bulk of the fluid may be smaller; but in this 
case care must be taken to stop the process before it has gone too far, as the 
crystals are apt to diminish, or even disappear, apparently owing to the forma- 
tion of a farther product of decomposition, and the same precaution is necessary, 
though to a less degree, with the cold solution. The crystals are purified by solu- 
tion in boiling alcohol. Chloropianyl may also be obtained by passing dry chlo- 
rine over fused opianyl. The gas is rapidly absorbed, hydrochloric acid is evolved, 
and the mass becomes gradually less and less fusible, so that the temperature of 
the oil-bath in which the tube is immersed must be slightly raised. After the 
action has gone on for some time, the current of gas must be stopped and the heat 
removed. If the action has been properly managed, the mass is highly crystal- 
line, and on solution in boiling alcohol gives crystals identical with those ob- 
tained in the wet way. In this case, also, care must be taken to stop the ac- 
tion at the proper point, for if it be continued too long, no crystals are obtained, 
and the fiuid solidifies into a resinous mass like Canada balsam. 
