Forensic medicine and toxicology : A comprehensive work on medical jurisprudence / By W. Bathurst Woodman and Charles Meymott Tidy, with eight full-page lithographic plates and one hundred and fifteen other illustrations.

  • Woodman, W. Bathurst (William Bathurst), 1836-1877.
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: Forensic medicine and toxicology : A comprehensive work on medical jurisprudence / By W. Bathurst Woodman and Charles Meymott Tidy, with eight full-page lithographic plates and one hundred and fifteen other illustrations. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    a large porcelain dish, and add to them about an equal weight of hydro- chloric acid and a little water, so as to make the whole into a thin paste. This must be heated on a water-bath. Add to the hot liquid about thirty grains of powdered chlorate of potash. Stir the mixture frequently, and from time to time continue the addition of the chlorate, until the mass becomes of a light yellow homogeneous character, adding now and then a little water, to make up for loss by evaporation. Continue to apply heat until the liquid ceases to give off any odor of chlorine. When cold, strain the liquid through linen. Wash the solid residue with hot water, and evaporate down the whole of the filtrate to a small bulk, and again filter. The next part of the process is to reduce any metallic oxide that may be in solution, and which will be present as a high oxide, to a lower grade of oxidation by heating with sulphite of soda. This being done, sulphu- retted hydrogen is to be passed through the solution, and the steps of an ordinary systematic analysis is then all that is necessary. We must just refer to one other process, viz., that suggested by Flandin, of breaking up the organic matters with heat and sulphuric acid. We are conscious that possibly some will object to the use of subacetate of lead in the process we have recommended; but inasmuch as the lead is not to be added until we have entirely completed our search for metallic poisons, we are of opinion that such objections are immaterial. Further, considering that the verdict of a jury, and consequently the life or death of a prisoner is frequently dependent on a chemical analysis, the results we obtain by our tests should in all cases be something more than questionable or doubtful reactions, about which a possible difference of opinion may exist. We consider it, therefore, unnecessary to enter into any descriptive detail, as others have done, of processes for the detection of millionths of a grain by such methods as the collection of microscopic sublimates, which we admit are as exquisitely beautiful, as they are, in our opinion, totally unfitted for practical investigations. If such poisons as arsenic, calomel, tartar emetic, corrosive sublimate, and oxalic acid, cannot be detected by their reactions in a test-glass, we are doubtful whether we should ever be justified in giving positive evidence of their presence on a criminal trial, by their microscopic form, and microscopic reactions. These are all very well as confirmatory tests, but nothing more. To build evidence entirely upon them in a criminal ease is dangerous in the extreme. Lastly, although we have given a detailed account of methods of syste- matic analyses, such as we ourselves adopt in toxicological investigations, it would not be fair to conclude this chapter without warning the operator that he must be prepared at every turn to encounter numerous difficulties, which are as impossible to be described as they are unexpected, and the remedies for which can alone be suggested by his own chemical knowledge and manipulative skill. (For Experiments on Dialysis in Toxicological Inquiries, see Medical Times and Gazette, Dec. 12th, 1863, p. 611.)