December 16, 1871.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS, 
485 
lowish-wliite precipitate with chloride of barium 
(BaCr0 4 ), and a purplisli-red precipitate with 
nitrate of silver (Ag 2 Cr0 4 ), and both these preci¬ 
pitates are soluble in diluted nitric acid. The solution 
also, when digested with sulphuric acid and rectified 
spirit, acquires an emerald green colour.] This last 
reaction results in the formation of the green sul¬ 
phate of chromium, sulphate of potassium, and a 
mixture of aldehyde and acetic acid, as the results 
of the oxidation of the alcohol. It is quite parallel 
with that by which valerianic acid is obtained by 
the oxidizing action of the same mixture upon amylic 
alcohol. A mixture of potassic chromate with an 
acid is, indeed, employed very frequently as an 
agent by which the oxidation of organic as well as 
other substances is effected; for example, in the 
conversion of cinnamic acid into hydride of benzoyl 
(see B. P. Styrax Prrep.), and in the volumetric 
process for the estimation of ferrous salts. Bichro¬ 
mate of potassium is one of a singular class of salts 
which contain the elements of the normal neutral 
salt and of the acid anhydride, e. (j. :— 
Bichromate of potassium . . 
Nordliausen sulphuric acid ' . 
Bisulphate of potassium . . 
Pyrophosplioric acid . . . 
CONTRIBUTIONS TO THE HISTORY OF THE 
OPIUM ALKALOIDS.* 
BY C. R. A. WRIGHT, D.SC. 
Lecturer on Chemistry in St. Mary's Hospital Medical 
School. 
Part III. 
1. Action of Ilyclriodic Acid on Codeia in Presence of 
Phosphorus. 
In Parts I. and II. of these researches the action of 
hydrobromic acid on codeia and its derivatives has been 
partially investigated; and as the action of this acid 
seems to be in some respects similar to, but in others 
different from that of hydrochloric acid, it appeared to 
be of interest to examine the action of hydriodic acid 
also. 
Some preliminary experiments on this subject, made 
two or three years ago in conjunction with the late Dr. 
A. Matthiessen, showed that when codeia is boiled with 
a large excess of strong hydriodic acid, no appreciable 
quantity of methyl iodide is evolved even after some 
hours’ treatment; a brown tarry mass containing much 
free iodine was produced, but at the time nothing fit for 
analysis was obtained from this; since then, Dr. Matthies¬ 
sen and Mr. Burnsidef have corroborated the non-for¬ 
mation of methyl iodide under these circumstances. 
If, however, phosphorus bo added simultaneously with 
the hydriodic acid, so as to prevent the accumulation 
of free iodine, methyl iodide is evolved at 100° and 
upwards in quantity close upon that required for the 
equation— 
C 18 H 21 N0 3 + III- CH 3 I + C 17 H 19 N0 3 : 
N '-—^ __/ v___✓ 
Codeia. Morphia. 
hitherto, however, no body of this latter formula has 
been isolated from the products of the reaction, the sub- 
* Read before the Royal Society, November 16, 1871. 
f Proceedings of the Royal Society, vol. xix. p. 71. 
K. 2 Cr9 0 7 , or 
K 2 Cr 0 4 . Cr 0 3 
( He, S 2 CL, or 
(h;so 4 '.so 3 
J K 2 S 2 0 7 , or 
(K 2 S0 4 .S0 3 
Ii 4 P 2 0 7 , or 
h 3 po 4 .hpo s 
stances ultimately formed being derived from a base 
containing H 2 more than morphia. 
The hydriodic acid was obtained, in the first instance, 
by the action of hydric sulphide on iodide and water ; in 
the dilute acid thus got iodine was dissolved, and the 
whole digested at a very gentle heat with phosphorus, 
more iodine solution being added from time to time; 
finally, the whole was distilled several times from potas¬ 
sium iodide. A colourless acid of sp. gr. L7 to 1-75, and 
containing 50 to 55 per cent, of HI, was thus obtained, 
and preserved colourless by keeping a stick of phosphorus 
in the bottle. The codeia used in these experiments was 
part of a further supply most liberally presented by 
Messrs. Macfarlan, of Edinburgh. 
On heating on the water-bath a mixture of 10 parts 
codeia, 30 to 50 of this acid, and 1 of phosphorus, the 
evolution of methyl iodide is noticed in a few minutes ; 
simultaneously the liquid becomes brown, indicating the 
separation of free iodine; after two or three hours the 
brown colour disappears, and the evolution of methyl 
iodide ceases. If the liquid be heated to gentle ebulli¬ 
tion, at first the same effects ensue, but more quickly; 
the resulting product, however, varies in composition, 
according to the temperature at which the reaction was 
effected. 
In one experiment 55 grms. of codeia yielded by con¬ 
densation 22-5 grms. of methyl iodide, the theoretical yield 
being 24 - 6 from crystallized codeia, C 1S II 21 N0 3 H 2 0; 
hence upwards of 90 per cent, of the theoretical yield 
was obtained. In order to prove the elimination of 
l-18th part of the carbon in the form of methyl iodide, 
4*3045 grms. of codeia, dried at 140° to 150° C., was 
heated to gentle ebullition with 30 grms. of 55 per cent, 
of hydriodic acid and about 2 of phosphorus; the vapours 
evolved were passed through a flask to condense aqueous 
vapour, and then through a combustion-tube filled with 
red-hot lead chromate, theC0 2 produced being absorbed 
in the usual way,—an aspirator being attached at the far 
end so as to create a diminished pressure throughout the 
apparatus, and thus guard against loss of methyl iodide 
vapour by leakage at any of the numerous corks and 
joints.* After three hours a current of pure oxygen 
was let through the apparatus to sweep out the last 
traces of methyl iodide vapour from the flasks, and en¬ 
sure the perfect combustion of deposited carbonaceous 
particles. t 
4-3045 grms. codeia thus gave 0-617 grm. C0 2 . 
0-3720 grm. codeia, burnt in the usual way, gave 
0-9830 COo. 
Found. 
Calculated. 
(A) Percentage of carbon | 
evolved as CIL 3 I . . ) 
3-91 
4-013 
(B) Percentage of carbon ) 
in codeia used . . j 
72-07 
72-241 
Ratio of A to B . 
3-91 
^ 2 : 07 
1 
I8 T 4 
jH)13_ 1_ 
72-241“ 18 
In another experiment not carried to a complete con¬ 
clusion, the C0 2 collected represented 3-7 per cent, of the 
codeia used. 
The methyl iodide produced was found, after washing 
with water, drying over CaCl 2 , and distillation, to be 
free from traces of dissolved phosphorus, to boil at 42° to 
45° C., and to correspond in every respect with the ordi¬ 
nary methyl iodide. 
If the reaction with hydriodic acid takes place on the 
water-bath, the resulting product appears to have the 
composition C 68 H 8f) I 2 N 4 0 12 ,4HI; but if the mixture be 
heated to gentle ebullition throughout, the tempera¬ 
ture not being allowed to exceed 110° to 115° from loss 
of aqueous fluid by evaporation, the substance obtained 
contains the elements of two molecules of water less, 
= C6 8 Hg 2 I 2 N 4 O 10 , 4 HI; whilst if the mixture be rapidly 
* This device may be applied with advantage to the ordi¬ 
nary processes for combustion, blowing out ot the tube as 
well as loss by traces of leakage being thus avoided. 
