CHEMICAL SCIENCE. 259 



thus, without diminishing its activity in breaking up protein compounds, 

 allows the dry matter subjected to alcohol, or other solvents of alkaloids, to 

 remain permeable. When baryta or lime is subsequently employed to 

 develop the alkaloid, either with or without ammonia salts, the chloride of 

 calcium does not interfere, and very pure alcoholic or ethereal solutions can 

 at once be obtained. 



He added, that he wished to express his accordance with the opinion of 

 Mr. Green, that the chemical experiments should be so conducted in the 

 search after poison which had caused death, as to eliminate from the tissues 

 that portion which had entered them, as being distinct in its effects from 

 the remainder found in the stomach or intestines, uncombined with protein 

 compounds. In cases of poisoning by corrosive poisons, the parts destroyed 

 or altered are easily observed and the results of many experiments had led 

 him to form the opinion, that the organic poisons, in their actions, leave 

 traces only little less strongly marked. 



In proof that strychnine is a much more stable body than has been 

 hitherto considered, Mr. Green cited from the Journal Medicale (18-50) an 

 account of toxicological experiments upon the bodies of various animals 

 which had been poisoned with minute doses of strychnine, in the tissues of 

 which that substance had been found. It was recognized after the lapse of 

 months, and even for years ; and, in one instance, was found in the bones, 

 and in the material of a wooden box in which an animal had been buried. 



COLORATION OF POISONS. 



Dr. Moffat, an English chemist, recommends the coloration of poisonous 

 substances with carbo-azotic acid, for the following reasons : 



" 1. Its coloring power is so great, that one grain is sufficient to impart a 

 distinct yellow color to 70,000 grains, or one gallon of water. 



" 2. The taste is so intensely bitter, that, in the above proportions, it im- 

 parts a very decided bitterness. 



"3. Carbo-azotic acid also possesses the valuable property, which is pecu- 

 liar to itself, of giving a yellow color to the skin, as if the person were suffering 

 from jaundice, when taken for three or four days in doses of one grain per 

 diem. This coloration would be easily distinguished from jaundice by any 

 medical man. 



" 4. The strong color which carbo-azotic acid imparts to food, urine, and 

 faeces, would serve as a proof that poison had been administered, especially 

 when detection of the particular poison employed might be doubtful, as in 

 the case of strychnine and other organic poisons. [Carbo-azotic acid can also 

 be detected in minute quantities by the appropriate tests.] 



" 5. A saturated solution of carbo-azotic acid in prussic acid does not ap- 

 pear to modify the therapeutic action of that potent remedy ; and twenty 

 drops of such solution impart a deep yellow color to one gallon of water. 

 [Ten drops tinge one gallon.] 



" 6. The color imparted to water is permanent. A bottle of water taken 

 from SIXTEEN gallons of water, to which ONE grain of carbo-azotic acid was 

 added on the 21st of March, 1856, upwards of fifteen months since, still retains 

 its yellow color. 



" 7. Carbo-azotic acid does not produce any deleterious effects upon tho 

 pystem. I have administered it until the skin, conjunctiva, urine, and saliva 



