260 EXAMINATION FOE AKSENIC 



employed for the chemical examination, to regard 

 three different cases as possible : 



I. The arsenious acid is found in the solid state in 

 the contents of the stomach and intestines, or in the 

 vomited matters. 



II. The poison is intimately and invisibly mixed 

 with, or dissolved in, the contents, &c., and can there- 

 fore no longer be found, or separated by mechanical 

 means, in the solid state. 



III. The stomach and intestines are empty or no 

 arsenic can be detected in them, since it has already 

 been absorbed into the mass of the blood, or into the 

 substance of the different organs. 



I. The arsenic is still to be found in the solid state, 

 and may be picked out or separated by levigation from 

 the contents of the stomach, &c.* This case is the 

 easiest of the three, since it is only to be proved that 

 the substance found is really arsenic. This may be 

 known by the grains or particles exhibiting the follow- 

 ing characters, after having been properly freed from 

 organic matter : 



1. The particles are generally milk-white, more rarely 

 clear and semi-transparent, hard, and brittle. 



2. A particle of arsenious acid, however small, when 

 introduced into a small tube closed at one end, and 

 heated in the edge of the spirit-flame, volatilizes and 

 recondenses farther up the tube, in the form of a white 

 sublimate which may be seen, especially when exam- 

 ined with a lens, by sunlight, to consist of very lus- 

 trous octohedral crystals. 



3. A small fragment placed upon red-hot charcoal, 

 is volatilized, emitting a powerful odor of garlic (on 

 red-hot glass or porcelain it volatilizes without garlic 

 odor, because it is not reduced to the state of metal). 



* Poisoning sometimes happens from commercial metallic arse- 

 nic (fly-poison, cobalt, &c.) Brownish-black grains or particles 

 should then be looked for, which are easily recognized as arsenic. 



