ACTION OF ACIDS ON QUINIA. 
209 
water present an opaline and blueish colour. This is owing to 
the affinity of the water for the acid causing a partial preci- 
pitation of the subsulphate, and permitting the molecules of 
the salt to acquire a degree of cohesion, and at the same time 
of tenuity, capable of producing a blueish colour.' " 
M. Andre does not admit this explanation to be satisfactory, 
and we are of the same opinion, because, in the first place, 
this opaline appearance takes place, not only with sulphuric 
acid, but also in different degrees with almost all the other 
acids; next, because it manifests itself in a quantity of fluid 
more than sufficient to dissolve the subsulphate itself if thus 
produced; and finally, because the aqueous solution of the 
subsulphate, as is stated by M. Andre, though perfectly clear 
in ordinary lights, also presents a blueish opaline reflection by 
reflected light. "Besides which, how does the sulphuric acid 
act on a solution of sulphate of quinia? According to the re- 
ceived opinion, the acid renders the salt neutral and after- 
wards acid; but with 0.1 of subsulphate and 75 grains of 
water at+60° F. a colourless solution is obtained, and the sul- 
phuric acid that is added, which ought to augment the solu- 
bility of the salt, if it was not already complete, appears on 
the contrary to diminish it, as the blueish tint which is mani- 
fested, is certainly owing to a precipitate so finely divided as 
to remain in suspension. It is known, however, that sulphu- 
ric acid facilitates the solution of subsulphate of quinia, for 
the crystallized bisulphate is evidently the most soluble; 
finally, how are these apparently contradictory effects to be 
explained, resulting as they also do from the action of other 
acids on the alkaloid, which do not alter its composition.'' 
M. Andre endeavours to explain these facts, by considering 
the quinia to be a sort of resinate of ammonia. He is of 
opinion: " That the first additions of acid tend to saturate a 
portion of the ammonia only, and that the resin still retaining 
enough of the base to be soluble, the fluid remains clear, as in 
the case of the subsulphate. But when the acid becomes pre- 
dominant, it is an indication that all the ammonia has entered 
into a new combination, whilst the resin in a free state re- 
VOL. II. no. in. 21 
