Page:Treatise on poisons in relation to medical jurisprudence, physiology, and the practice of physic (IA treatiseonpoison00chriuoft).pdf/547

 hind-legs, convulsions of various degrees of intensity, from simple tremors to violent tetanus, and a peculiar slumber, in the midst of which a slight excitement rouses the animal and renews the convulsions. These symptoms are produced in whatever way the poison enters the body, whether by the stomach, or by a wound, or by direct injection into a vein, or by the rectum. In man, convulsions are sometimes excited; but much more commonly simple sopor and coma.

According to the inquiries of M. Charret, which were extended to every class of the lower animals, opium produces three leading effects. It acts on the brain, causing congestion, and consequently sopor; on the general nervous centre as an irritant, exciting convulsions; and on the muscles as a direct sedative. It is poisonous to all animals,—man, carnivorous quadrupeds, the rodentia, birds, reptiles, amphibious animals, fishes, insects, and the mollusca. But of its three leading effects some are not produced in certain classes or orders of animals. In the mammalia, with the exception of man, there is no cerebral congestion induced, and death takes place amidst convulsions. In birds there is some cerebral congestion towards the close; but still the two other phenomena are the most prominent.

It has been rendered probable, by what is stated above, that opium enters the blood. The question, therefore, naturally arises, whether its presence there can be proved by chemical analysis? But considering the imperfection of the processes for detecting it when mixed with organic substances, no disappointment ought to be felt if this proof should fail in regard to so complex a fluid as the blood. The only person who has represented himself successful in the search is M. Barruel of Paris. He examined the urine and blood of a man under the influence of a poisonous dose of laudanum, amounting to an ounce and a half; and procured indications of morphia in both. When three ounces of urine were boiled with magnesia, and the insoluble matter was collected, washed, dried, and boiled, in alcohol, the residue of the alcoholic solution formed a white stain, which became deep orange-red on the addition of nitric acid. The blood was subjected to a more complex operation. One pound and ten ounces of it were bruised in a mortar, diluted with two pounds of water, strongly acidulated with sulphuric acid, boiled, filtered, and washed. The filtered fluid was saturated with chalk, and the excess of carbonic acid driven off by heat. The fluid was then filtered again, and after being washed with water, was acted on by diluted acetic acid. The acetic solution left on evaporation a residue which was repeatedly acted on by alcohol; and the residue of the alcoholic solutions was treated with pure alcohol and carbonate of lime. The new solution when filtered and evaporated left several small white stains, which became orange-red with nitric acid. These results have been since contradicted by M. Dublanc. He in vain sought for morphia in the blood and urine of people who were taking