62 DR ANDERSON ON CODEINE, AND 
is precipitated from all its salts by ammonia; it does not, however, fall imme- 
diately, but is slowly deposited in small transparent crystals. 
II. Salts of Codeine. 
Hydrochlorate of Codeine.—This salt is readily obtained by saturating hot 
dilute hydrochloric acid with pure codeine. If the solution has been sufficiently 
concentrated, it becomes nearly solid on cooling, but if more dilute, the salt is 
deposited in radiated groups of short needles, which, under the microscope, are 
found to be four-sided prisms terminated by dihedral summits. It is never ob- 
tained in large crystals, even when considerable quantities are crystallised. These 
crystals are soluble in 20 times their weight of water at 60°, and in less than their 
weight of water at 212°. Codeine is precipitated from the saturated cold solution 
immediately by potash; ammonia gives no precipitate, but after some time 
colourless crystals are deposited. The crystallised hydrochlorate of codeine con- 
tains water of crystallisation, and presents some curious anomalies in its rela- 
tions to that fluid. When dried in the air, it retains four equivalents of water, one 
of which escapes at 212°, but the remaining three are only expelled at 250°, and at 
the same time the salt loses acid, and acquires an alkaline reaction. It would 
appear, also, that under certain circumstances, the salt is deposited in anhydrous 
crystals, as one analysis of it dried at 212°, gave numbers corresponding to the an- 
hydrous salt. I could not, however, again succeed in obtaining it in this condition ; 
but many analyses were made which gave results lying between those of the anhy- 
drous and crystallised salts, and the only means of explaining the discrepancy is by 
supposing that the two sorts of crystals had been deposited simultaneously and in 
variable proportions. The following is the analysis of the salt dried at 212° :— 


6:035 grains hydrochlorate of codeine gave 
13:208 ... of carbonic acid, 
3°830 ... of water. 
Experiment. Calculation. 
—_- °°? _=<=S ee 
Carbon, : : 59°68 59-58 Cy, 216 
Hydrogen, : - 7:08 6.89 H,, 25 
Nitrogen, : oa 3°86 N 14 
Oxygen, : : eh 19°88 0, 72 
Chlorine, : é ce 9°79 Cl 35:5 
100-00 362°5 
10-735 grains of the salt lost, at 212°, 0°31 grains of water=2°88 per cent. 
One equivalent of water gives by calculation 2:42 per cent. The formula of the 
air-dried salt is therefore C,, H,, NO, H Cl+4 HO. 
The anhydrous salt gave the following results. Of these, No. I. is the salt 
obtained by direct crystallisation from the morphia mother-liquor ; No. II. is that 
