GASEOUS.
Irritant poisons, when taken in ordinary doses, occasion speedily violent vomiting and purging, preceded, accompanied, or followed by intense pain in the abdomen, commencing in the region of the stomach. The oorrosive poisons, as distinguished from those in a more limited sense termed irritant, generally produce their result more speedily, and give chemical inclinations ; but every corrosive poi son acts as an irritant in the sense here adopted.
Narcotic poisons aot chiefly on the brain or spinal marrow. Either immediately or some time after the poison has been swallowed, the patient suffers from headache, giddiness, paralysis, stupor, deli rium, insensibility, and, in same instances, oonvnl sions.
3. The effeots of one class are, however, sometimes produced by the other,—roore commonly as se condRry, but sometimes even as primary, symptoms.
The evidence of poisoning, as derived from eymptonnt, ie to be looked for chiefly in the sudden ness of their occurrence; this is perhaps the most reliable of all evidence derived from symptoms in oases of criminal poisoning, see Taylor, Pois. 107;
Christison, Pais. 42 ; though none nf this class of evidence can be considered as furnishing any thing better than a high degree of probability ; the regu larity of their increase; this feature is not uni versal, and exists in many diseases; uniformity in their nature; this is true in the ease of oompars tively few poisons; the symptoms begin soon after a meal ; hut sleep, the manner of administration, or certain diseases, may affect thie rule in the case of some poisons ; when eeveral partake at the same time al the same poisoned food, all suffer from similar symptoms, 2 Park. Cr: Cas. N. Y. 235 ; Taylor,