By an Act of Parliament (14 Vict. cap. xiii. sec. 3), it is ordered that if sold in small quantities, it must be mixed with the sixteenth part of its weight of soot, or the thirty-second part of its weight of indigo, ten pounds being the smallest quantity allowed to be sold unmixed. The presence of this admixture must be remembered, as a medical man may be led into an error when the vomited matters are coloured blue, black, or green, from the mixture of bile with the indigo. Arsenic is not, as a rule, a corrosive poison. One case is, however, on record where it acted as a corrosive, but the purity of the arsenic in that case has been questioned. Its action is that of an irritant, causing inflammation in the stomach and bowels of those who have taken it; and it appears that fatal effects are produced whether the poison be swallowed or introduced into the system in any other way--_e.g._ by injection into the rectum or vagina, or applied to the surface of the body. Some observers hold that arsenic cannot be considered in the light of an accumulative poison, others that it is so to a certain extent, and that its elimination is not so rapid as was previously thought. Given in medicinal doses, it is eliminated in from fifteen to twenty days. Hence, in cases which have survived the immediate action of the drug, no arsenic may be found in the body fifteen days after its fatal administration. This is a fact of considerable importance. In the case of Pierre Emile L‘Angelier, for whose murder Madeline Smith was tried, Dr. Penny found 88 grains in the stomach, although the deceased survived eight or ten hours after the probable period of taking the poison, and vomited repeatedly during that time. At the above trial, the question was suddenly raised, that if such a large quantity was found after death in the stomach, it was scarcely possible to infer the administration of a much larger quantity; and thus, that the quantity must have been larger than another party could have secretly administered, or naturally would attempt to administer. Drs. Mackinlay and Wylie, of Paisley, obtained 60 grains, and Sir R. Christison 30 grains more, from the stomach of a man poisoned by arsenic administered in whisky-punch sweetened, the arsenic being kept in suspension by constant stirring. Symptoms of Arsenical Poisoning