Trial of John Tawell for the murder of Sarah Hart by prussic acid : with remarks / by D. Skae.

  • Skae, David, 1814-1873.
Date:
[1845]
Catalogue details

Licence: Public Domain Mark

Credit: Trial of John Tawell for the murder of Sarah Hart by prussic acid : with remarks / by D. Skae. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    arsenic, the mercurial salts, and other metallic poisons, but no trace of any of those substances 'was detected. Some of the contents of the stomach were then distilled from a sand-bath, and tested for prussic acid, of the presence of which unequivocal evidence was obtained by the formation of the Prussian blue. Part of the contents of the stomach was also distilled from a water-batli, made Avith a boiling solution of chloride of sodium ; the clear fluid which passed over gave a deep blue, with sulphate of iron, potassa, and muriatic acid. A portion of this liquid was treated with nitrate of silver, and an insoluble white precipitate, having the properties of the cyanide, was obtained. This precipitate was afterwards treated with muriatic acid, and subjected to distillation, and the distilled fluid smelt of prussic acid. The odour of prussic acid was not perceived at any previous step of the analysis by any of those present—nor in the contents of the stomach itself, before they were analyzed, although Mr Cooper admitted that the acid must have been present in a free state, as the presence of free muriatic or acetic acid was indicated by litmus. On being asked Avhether he agreed with Mr Taylor in his Medical Jurisprudence that the odour of prussic acid may be found when all other tests fail to prove the presence of that acid, Mr Cooper said he did not believe it, and that his experience would lead him to a contrary conclusion. Sometimes he could not smell prussic acid at all, but recognised it only by its producing a spasmodic constriction about his throat. The capability of perceiving the odour de- pended very much upon the state of the nasal organ at the moment. Mr Cooper, and the three medical Avitnesses ex- amined, all concurred in stating that the contents of the stomach smelt of beer or porter, and they considered the odour of the porter sufficient to conceal that of the poison. One of the witnesses had tried the experiment of mixing some prussic acid Avith a pint of porter, and, although he considered his sense of smell very acute, he could not then recognise the odour of the acid. From the quantity of cyanide of silver obtained from about a third-part of the contents of the stomach, Mr Cooper conceived that the Avhole contents must have contained one grain of anhydrous prussic acid, or about tAvcnty grains of Scheele’s acid, or fifty of the preparation of the London pharmacopoeia. Some pieces of undigested apple were found in the stomach, but no pips. Mr Cooper made some experiments on apple-pips, with reference to the supposition that the prussic acid in this case might have been produced from that source. From the pips of fifteen apples he obtained only a trace of prussic acid, a quan- tity Avhicli he stated Avas inappreciable. All the medical witnesses concurred, Avithout hesitation, in ascribing death to poisoning with prussic acid.