Observations and experiments with the microscope, on the chemical effects of chloral hydrate, chloroform, prussic acid, and other agents, on the blood / by Thomas Shearman Ralph.

  • Ralph, T. S. (Thomas Shearman), 1813-1892.
Date:
[1871?]
Catalogue details

Licence: Public Domain Mark

Credit: Observations and experiments with the microscope, on the chemical effects of chloral hydrate, chloroform, prussic acid, and other agents, on the blood / by Thomas Shearman Ralph. 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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    action of the new agent should be such as we can trace out without encountering serious difficulty as to its interpretation. I now proceed to the demonstration of some chemical changes in the blood, produced by means of different agents ; the effects of which have been hitherto entirely unknown, ,and which will prove suggestive to the mind of the medical practitioner as soon as he shall have presented to him a further series of experiments carried out after the mode of investigation which I have endeavoured to follow, namely : the general action of a chemical substance on the blood withdrawn from the body, and traced out by the microscope ; and also the investigation of the action of the same agent on the blood, after it has circulated through the animal economy, having been thereby subjected to the continuous action of air during its passage through the lungs. In the former instance, we obtain a general kind of action on the blood ; in the latter, more positive or distinct effects are presented to our notice, as I shall endeavour to point out by and bye. The examination of the blood drawn from the circulation and subjected to the action of a chemical agent, does not suffice to show us all that may be produced on it by that agent, and we need, if it is possible, to ascertain and compare its effects after it has circulated in the system. This is true, however, only to a certain extent, for we know that magenta has a remarkable effect on the blood when added to it; but we find no trace of its effects on that fluid, when we inject it under the skin, or pass it into the stomach with a view to its absorption and subsequent action on the blood, as the experiments of Professor Halford go to show. I now pass on to the examicationl have made of the action of one important chemical agent which has only lately been brought before the notice of the medical profession, both here and at home, or rather in Europe. I mean Chloral; or as its more chemical name is supposed to be “ Trichloric Aldehyde.” This substance is now in use as an Hydrate, and its action has been stated to be somewhat like Chloroform. When an alkaline solution is added to it, Chloroform is set free ; hence its proposer, Liebreich, suggested its use : that meeting with alkaline elements in the blood, it might become decom- composed into Chloroform This theory, which is a very taking one, was no doubt the cause of the experimental use of this sub- stance ; the general experience, however, of the profession is against the idea that it acts as an anaesthetic, but only as a true hypnotic. I feel inclined to the opinion that though it appears almost certain that Chloroform is eliminated in the blood by its decomposition ; yet that the action of that agent is considerably modified by the attendant chemical change which necessarily accompanies the decom- position of this agent in the blood. If it is correct that the Hydrate of Chloral is decomposed by the alkaline state of the blood ; then it follows as certainly that the resulting compounds must be Chloroform and a formate of some alkali. And if we regard the presence of alkalinity to be normal in the blood, then we obtain not only the chemical or physiological action of Chloroform, but we have also to