THE ANALYST. 111 NOTE ON THE DETECTION OF STRYCHNINE. BY ALFRED H. ALLEN, F.C.S. Bead at the Meeting of the Society of Public Analysts, PZymouth, on the 17th August, 1877. IN my practice I have had a great variety of animals submitted to me t o be tested for poison. The number of cases in which strychnine has been found is probably greater than that all other cases pat together, and as I find some chemists profess a difficulty in112 THE ANALYST.applying the tests for strychnine, I believe I may do a service by publishing my method of procedure, though it has no claim to novelty, except, perhaps, in one or two details. The matter to be tested is, first of all, digested on the water-bath with water and Borne acetic acid. Alcohol is next added in sufficient amount to facilitate the filtration of the liquid.The filtered liquid is evaporated nearly to dryness, water again added, and the solution filtered. The clear liquid is again evaporated to a syrup, strong alcohol added, and the liquid once more passed through a filter, The alcoholic solution is evaporated, the residue taken up with a small quantity of water, the solution filtered, if necessary, and treated with soda in moderate excess.The alkaline liquid is next shaken wit8h ether, the etherial layer removed with a pipette and allowed t o fall-one drop at a time-into a porcelain basin, heated by hot water. I n this manner the strychnine is concentrated in a comparatively small space, instead of being spread out over a large surface. When the ether has all evaporated and the basin become cool, the residue is treated with concentrated sulphuric acid.* Bichromate of potassium is decidedly the worst, in ruy opinion, of all those commonly used.Dioxide of lead is not very satisfactory. Powdered ferricyanide of potassium gives a very good result, but requires to be used carefiilly. Finely powdered dioxide of manganese gives the best results in my hands.It should be added to the sulphuric acid in moderate amount, so as not to obscure the violet coloration, and the mixture should be well stirred. The changes of color occur much less rapidly with the manganese dioxide than with ferricganide. I have sometimes used dialysis for the original extraction of the strychnine, but a9 ths aqueous liquid requires t o be subsequently treated in much the same manner as already described, the loss of time involved is seldom accompanied by any compensating advantage. Dr. Muter said he had found that the agitation of the acid solution of the strychnine with ether, to remove indifferent matters, greatly facilitated the subsequent purification of the strychnine. bilr. Thomson had obtained good results bv preparing chromate of strychnine, and subsequently treating that salt with sulphuric acid. There is considerable choice in the oxidising agent employed. This is in some cases an advantage.