Lectures on the influence of researches in organic chemistry on therapeutics : especially in relation to the depuration of the blood / delivered at the Royal College of Physicians, by Golding Bird.

  • Bird, Golding, 1815-1854.
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on the influence of researches in organic chemistry on therapeutics : especially in relation to the depuration of the blood / delivered at the Royal College of Physicians, by Golding Bird. 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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    to form sulphocyanide of potassium. The atoms thus deserted unite to form oil of garlic, the change being at once evident from the characteristic onion-like odour evolved. The rocks of New Jersey are covered by a beautiful ericaceous plant, the Gaultheria procumbens, whose flowers exhale an aro- matic odour something between that of the hyacinth and cinnamon. By distilling them, the aromatic oil I now shew you is obtained. Its agreeable perfume has made it an article of commerce. On submitting it to analysis, it is found to consist of C16 H8 °6- Now, on subtracting from this the formula for the oxide of methyle, the base of the pyroxylic spirit or wood naphtha, we obtain the formula which expresses the composition of the spiroylic or salicilic acid :— C H O Oil of Gaultheria . 16 8 6 Oxide of methyle .231 Salicilic acid . . 14 5 5 This salicilic acid is obtained by many •different processes. By heating indigo or salicine, or the oil of Spicaea ulmaria, with caustic potass, we obtain the salicylate of potass, from which the acid is readily precipitated by hydrochloric acid. In this form it resembles benzoic acid, and the spe- cimen I now shew you was thus procured. If we digest the oil of gaultheria with potass, it is immediately resolved into its proximate constituents; the oxide of methyle unites with water to form pyroxylic spirit, whilst a salicylate of potass is left. The magnificent specimen of salicylic acid I now shew you was obtained from the oil of gaultheria, by that excellent chemist Mr. Mason, to whom I am indebted for it. Now, from the view thus taken of the constitu- tion of this oil, it is easy to prepare it arti- ficially. Accordingly, on placing in a retort some of the salicylic acid I prepared from salicine, with pyroxylic spirit (hydrated oxide of methyle) and a little sulphuric acid, and applying heat, the oil of gaultheria distils over, and may at once be recognised by its odour. Thus, by our art, the aromatic oil which gives the odour to the flowers of an ericaceous plane of New Jersey, and deve- loped under the influence of its vital che- mistry, is prepared independently of vitality in our glass vessels, from bodies obtained from the destructive distillation of wood and the ignition of indigo or salicine with potass.