418 
CHLORODYNE. 
The dose of chloroform in Squire’s is not unreasonable ; but that of morphia, 
viz. the l-200th to the l-70th of a grain, is palpably absurd, and so homoeopathic 
that it might practically be omitted from the compound. The only conclusion 
fairly deducible from a comparison of the two formulae is, that neither of them 
can be said to represent the well-known Browne’s chlorodyne. 
The results of an examination I have recently made of the genuine compound 
may not be uninteresting to pharmacists. 
The positive detection and isolation of the alkaloids in complex organic mix¬ 
tures is not always a very easy task, more especially when they exist in small 
proportions. I started with the intention of simply satisfying myself of the 
presence or absence of morphia ; however, the examination gradually developed 
itself, and ultimately I managed to make out with tolerable precision what I 
believe to be the actual composition of this preparation. 
Genuine chlorodyne has a sp. gr. of 1/216, and reddens blue litmus paper. 
Distilled over a water-bath, it yields an opaque distillate, evidently a mixture 
of two or more fluids; on the addition of an equal volume of water, the distillate 
separates into three distinct layers. The upper one has an ethereal pepperminty 
odour and taste, and is in fact oil of peppermint dissolved in ether. The ether 
may be recognized by the ready inflammability of its vapour. 
The middle layer, separated by a pipette and gently heated with a few drops 
of hydrochloric acid and potassium chromate, gradually assumes a green colora¬ 
tion, owing to the reduction of the chromate, and indicating the presence of 
alcohol—a tincture probably. The odour of hydrocyanic acid is given off during 
the heating. This layer also gives a precipitate with silver nitrate, insoluble in 
nitric acid and sparingly soluble in ammonia, revealing hydrocyanic acid.* 
The lowest layer, heated gently with caustic potash, yields with silver nitrate 
a precipitate insoluble in nitric acid, and which blackens by the further appli¬ 
cation of heat, owing to the reduction of the silver formate, indicating the 
presence of chloroform. 
The residue in the retort, consisting of a dark, semifluid paste, dissolves in 
water, and has a very pungent, peppery taste of capsicum. This aqueous solu¬ 
tion gives a precipitate with alcohol, basic plumbic acetate, and ammonium 
oxalate, revealing the presence of gum, aud also gives the usual glucose reaction 
with the potassio-cupric tartrate. The non-volatile alkaloids would of course 
be found in the residue in the retort after distillation, but the colouring matter 
adheres to its solution in water, etc., with such pertinacity as to render the 
usual tests very unreliable, and therefore a fresh sample of the original compound 
is required, to satisfactorily determine their presence. 
The following is the plan I adopted to isolate the alkaloids 
Digest the chlorodyne with twice its volume of alcohol, containing a few drops 
of acetic acid at a warm temperature, say 50° to 60° C. for four or five hours, oc¬ 
casionally shaking the mixture. The whole of the gum and much of the colouring 
matter are thus precipitated. After filtration, the alcoholic solution is gently 
evaporated until it thickens, being careful not to push the evaporation too far, 
as the glucose in the solution very soon blackens. To this semi-liquid extract 
is added water, and the whole gently heated with a solution of potassium bicar¬ 
bonate, containing a little caustic potash, and set aside to deposit. 
This precipitate of alkaloids is separated by filtration and digested with ether, 
until nothing more is dissolved. All the alkaloids likely to be present in chloro- 
* In tlie preliminary examination of complex organic mixtures for hydrocyanic acid, 
Schonbein’s guaiaco-cupric test promises to be useful. Thus, the presence of hydrocyanic 
acid in chlorodyne may be determined in a few seconds by this test. It must be borne in 
mind that free nitric acid and chlorine give the same reaction, but not their compounds, 
neither do acetic, hydrochloric, sulphuric, or phosphoric acids. 
