On poisons, in relation to medical jurisprudence and medicine / by Alfred S. Taylor.

Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: On poisons, in relation to medical jurisprudence and medicine / by Alfred S. Taylor. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    SALINE MEDICINES POISONOUS IN LAIIGL DOSES. copper, tin, zinc ami antimony, which are only jmisonons when administered in very large doses. Nitre, it is well known, exerts a lioisonous action only in large, while arsenic is poisonous in small doses; but in a medico-legal view, whether a person die from the effects of an ounce of nitre, or of five grains of arsenic, is a matter of little importance. Each substance must be regarded as a poison, differing from the other oidy in its degree of activity and perhaps in its mode of operation. The resiJt is the same; death is caused by the substance taken, and the quantUij required to kill cannot therefore be made a ground for distinguishing a poisonous from a non-poisou- ous substance. If, then, a medical witness be asked, “ What is a poison ?” he must beware of adopting this common definition, or of confining the term poison to those substances ouly that ojicratc in small doses. The fact that a poison has been commonly regarded as a substance which produces serious effects when taken in small quantity, has induced many who have adopted this arbitrary view to assert, that certain substances which have actually been known to cause death, are not poisons; and tliis doctrine has been apparently strengthened by the fact, that were not some such distinction adopted, it would be difficult to separate the class of poisons from bodies which arc reputed inert. In answer to this view, it is perhaps sufficient to show, that there is no good reason for assuming this as the distinguishing character of a ])oisou; for it is impossible, even among substances universally admitted to be poisonous, to make any dinsion according to the effects produced by the quantity taken. In relation to the quantity required to operate fatally, the difference is not so great between cream of tartar and oxalic acid as between oxalic acid and strychnia. If we consider nitre and cream of tartar to be poisons, there seems to be no good reason for excluding common salt (the chloride of sodium). Medicnl practitioners would scarcely be prepared to admit this last-mentioned substance into the class of poisons; but it is to be observed, that in a very large dose it is capable of acting as a powerful irritant, and of inflaming the mucous membrane of the alimentary canal to the same extent as much smaller doses of other well-known irritants. An instance of Common salt having caused death occiurcd in the north of England in the year 1839. A young lady swallowed, it is supposed, about half a poimd of this substance, for the purpose of destroying worms. It was considered to be a harmless substance, according to the common notion; but in the course of about two hours some farming .sj-mptoms made their ap- jicarance, and medical assistance was sent for. She was found to be in a state of general paralysis; and although the stomach-pump and other antidotal means were speedily employed, she died in the course of a few hours. After death there were found the post-mortem changes generally indicative of the effects of a violent iiTilaiit on the alimentary jiassagcs. (Medical Gazette, 1839-40, i. 559.) This case is deserving of atten- tion, not merely from its novelty, but from the evidence which it