The detection of strychnine in carcasses and corpses

Abstract

(1) In order to express a definite opinion as to the presence or absence of strychnine in purified extracts of specimens of organs, etc., it is essential that the following tests be conducted: (a) taste test, (b) colour test, and (c) a biological test. Immature white mice are for various reasons more suited to the biological test than frogs, (Rana esculenta, Rana pipiens, Rana palustris, Rana aqualensis). It is definite that very unreliable and inaccurate results will be obtained if both the colour and biological tests for strychnine are not applied to extracts as a large number of chemical substances, including ptomaines, are known which yield positive results either with the colour test, or with the biological test for strychnine. Many of these substances also have a bitter taste. The greatest care should be exercised in expressing an opinion as to the presence of strychnine in decomposed carcasses and corpses. The author isolated a strychnine-like ptomaine(s) from a decomposed liver, which was known not to contain any strychnine. This ptomaine(s) had a bitter taste and gave a positive sulphuric acid-potassium bichromate test for strychnine. The results of taste, chemical and biological tests with unidentified and identified ptomaines are recorded. (2) If three weeks old white mice are used in the biological test at least 0.008 mgm. strychnine sulphate is required in order to produce recognisable strychnine spasms in a mouse weighing 10 to 12 gm. With 14 day old white mice weighing 5 to 6 gm. 0.004 mgm. strychnine sulphate is detectable. In order to achieve reliable results in the detection of strychnine in purified extracts of organs, etc., at least 0.011 mgm. strychnine sulphate should be present as approximately 0.007 mgm. is required for the Otto test and 0.004 mgm. For the biological test if this is conducted upon 14-day old white mice weighing from 5 to 6 gm. If three-weeks-old white mice are employed the least amount of strychnine detectable in extracts is 0.015 mgm. if both the Otto and biological tests are conducted. (3) The symptoms of strychnine poisoning in white mice and in the frog (Rana aqualensis) are described. (4) The taste test and chemical and biological tests for strychnine are discussed. (5) Factors responsible for the disappearance of strychnine from corpses and carcasses are discussed. Of four dogs killed with strychnine and exhumed ten weeks after death strychnine was detectable in three carcasses, whilst of four carcasses exhumed eighteen weeks after death only one was positive for strychnine. Eleven months after death eight carcasses of dogs killed with strychnine were exhumed and strychnine was detectable in only four of these. Subsequent exhumations of carcasses of dogs killed with strychnine and of control dogs are to be conducted. (6) Methods of extracting strychnine from carcasses and corpses and of purifying these extracts are discussed. (7) In fresh carcasses and corpses the most suitable organs for analysis for the presence of strychnine are liver, stomach, spleen, lung and the central nervous system; also the urine. (8) In two out of three dogs, which had received strychnine as a tonic, strychnine was detectable in the liver and stomach (plus contents). (9) A large number of chemical substances, which resemble strychnine chemically and biologically, are discussed.