Where the poison has been administered internally, we shall find the stomach and intestines presenting an appearance of inflammation, very similar to that which we have described as the general result of corrosive poisons. Marks of inflammatory action, and sometimes ulceration, will be also discovered in the urinary and genital organs; especially in those cases where the person dies shortly after the ingestion of the poison.
Methods of detecting the presence of Cantharides.
Where the poison has been administered in substance, we shall generally discover some of its particles mixed with the ejected matter; or, after death, adhering to the coats of the stomach, or to the folds of the intestines, and which may be easily identified by their peculiar green and brilliant hue. If the poison should have been administered in the form of infusion, or tincture, our chemical resources will fail us, and we must rely alone upon the evidence furnished by the symptoms, and organic lesions.
Phosphorus.
This singular substance was accidentally discovered by Brandt, a chemist of Hamburgh, in the year 1669,[[340]] as he was attempting to extract from human urine a liquid capable of converting silver into gold. It was also subsequently discovered by Kunkel and by Boyle, without these latter chemists having, in any way, participated in the researches of each other.
Phosphorus, when pure, is semi-transparent and of a yellowish colour; but when kept some time in water, it becomes opaque externally, and then has a great resemblance to white wax. Its consistence is nearly that of wax; it may be cut with a knife. Its mean specific gravity is 1·770. It generally occurs in sticks. When exposed to the air, provided the temperature be not lower than 43°, it emits a white smoke, which has the smell of garlic, and is luminous in the dark. This smoke is more abundant, the higher the temperature is, and is occasioned by the gradual combustion of the phosphorus. When heated to 148° it takes fire, and burns with a very bright flame, and gives out a great quantity of white smoke, which is phosphoric acid. Oils dissolve phosphorus, provided the temperature be a little raised. Water has no effect upon it, unless it be aerated, when it renders the surface of the phosphorus opaque and white, which in a short time becomes red. This change depends upon oxidation.
Symptoms of poisoning by Phosphorus.
This substance, whether introduced into the stomach in its pure form, or dissolved in oil, will occasion the most violent symptoms, from its escharotic action,[[341]] It has been employed in medicine,[[342]] in a state of minute division, in the dose of one-fourth of a grain, and is said by Leroi to be very efficacious in restoring and establishing the force[[343]] of young persons exhausted by sensual indulgence, and of even prolonging the life of the aged.[[344]] It has also been given as a stimulant in local fevers. We are, however, greatly inclined to question the safety of such a practice, notwithstanding the diminutiveness of the dose. The reader will find some interesting cases of poisoning by phosphorus, translated from the German work of Weickard, in Hooper’s Medical Dictionary, under the consideration of that article. Should such a case present itself for the investigation of the forensic physician, he will not find any difficulty in identifying the substance; its external character, its smell, and, above all, its peculiar property of yielding luminous vapour, are too palpable and distinctive, to admit the possibility of error.
Mechanical Poisons—Powdered glass—Enamel powder—Chopped hair, &c. &c.
We have already examined the pretensions of these bodies to the rank of corrosive poisons, (page [145]) and we should have not reverted to the subject, but from a wish to introduce the account of “a case of Schirrus in the intestines, arising from hairs remaining in the canal,” as related in the Edinburgh Medical Journal,[[345]] by Dr. Burrell, and which had, on the former occasion, escaped our notice. The subject of this history, Laurence Harding, æt. 35, being a private soldier, was admitted into the regimental hospital, for an unrelenting constipation of the bowels; but it appears also that he had been affected with dyspeptic symptoms, and pain in his abdomen, for several years; which pain was aggravated by the ingestion of solid food. He received but little benefit from the remedies that were administered, his strength gradually declined, and, about a month after his admission, he expired.