POISONS : THEIR EFFECTS AND DETECTION. 
[§ 762. 
extending so far as gangrene. As a rule, putrefaction is remarkably 
retarded, and is especially slow in those organs which contain arsenic ; 
so that, if the poison has been swallowed, the stomach will retain its 
form, and even, to a certain extent, its natural appearance, for an 
indefinite period. In corpses long buried of persons dying from arsenical 
poisoning, the ordinary process of decay gives place to a saponification, 
and such bodies present a striking contrast to others buried in the same 
graveyard. This retardation of putrefaction is what might, a priori, be ex¬ 
pected, for arsenic has been long in use as a preservative of organic tissues. 
§ 762. Physiological Action of Arsenic. — The older view with 
regard to the essential action of arsenic was, without doubt, that the 
effects were mainly local, and that death ensued from the corrosive 
action on the stomach and other tissues—a view which is in its entirety 
no longer accepted. Nevertheless, it is perfectly true that arsenic has a 
corrosive local action : it will raise blisters on the skin, will inflame the 
tongue or mucous membranes with which it comes in contact ; and, in 
those rapid cases in which extensive lesions have been found in the 
alimentary canal, it can hardly be denied that instances of death have 
occurred more from the local than the constitutional action. In the vast 
majority of cases, however, there is certainly insufficient local action to 
account for death, and we must refer the lethal result to a more profound 
and intimate effect on the nervous centres. The curious fact that, when 
arsenic is absorbed from a cutaneous surface or from a wound, the 
mucous membrane of the stomach inflames, is explained by the absorption 
of the arsenic into the blood and its separation by the mucous membrane, 
in its passage exerting an irritant action. The diarrhoea and hypersemia 
of the internal abdominal organs have been referred to a paralysis of 
the splanchnic nerves, but Esser considers them due to an irritation of 
the ganglia in the intestinal walls. Binz has advanced a new and 
original theory as to the action of arsenious acid ; he considers that the 
protoplasm of the cells of many tissues possesses the power of oxidising 
arsenious acid to arsenic acid, and this arsenic acid is again, by the same 
agency, reduced to arsenious acid. In this way, by the alternate oxidation 
and reduction of the arsenious acid, the cells are decomposed, and a 
fatty degeneration takes place. Thus arsenic causes fatty changes in 
the liver, kidney, and other cells by a process analogous to the action of 
phosphorus. T. Araki 1 also considers that both arsenic and phosphorus 
lessen oxidation, and points out that lactic acid appears in the urine 
when either of these poisons is taken, such acid being the result of 
insufficient oxidation. A notable diminution of arterial pressure has 
been observed. . In an experiment by Hugo, 2 -03 grm. of As 2 0 3 was 
injected intravenously, the normal arterial pressure being 178 mm. 
Ten minutes after injection the pressure sank to 47 mm. ; in sixteen 
1 Zeit. physiol. Chem., xvii. 311-339. 2 0v cit 
