A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer.

  • John Hunter
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    blood for the purposes of animal life: the time that we can live without air, or breathing, is shorter than that in which we die from a defect in any other natural operation ; breathing, therefore, seems to render life to the blood, and the blood continues it in every part of the body. This nicety is not nearly so great in many of the more imperfect animals. The amphibia have not this division of lungs, nor does the whole of the blood pass through the lungs in them, and they can live a considerable time without breathing. This, at present, I only mention as a fact, not meaning to give my opinion of the mode of preserving life, either in the blood or body, by the appli- cation of air to it; though I will say that mere life in both is sup- ported by the air, and probably few of the other properties con- nected with the blood depend so much upon air as its life. But we may observe, that it was not necessary for the blood to undergo this change to render it fit for every purpose in the animal economy, for we find that venal blood answers some purposes: thus, the blood from the intestines, spleen, etc., going to the liver, as we sup- pose for the secretion of the bile, shows that venal blood will do for some secretions, though probably not absolutely necessary.* This application of venal blood is a saving of blood ; and it is not neces- sary for the formation of bile that the venous blood should proceed from the parts above-mentioned, for in birds, amphibia, etc., other veins, besides those, enter the liver. I have shown that several substances mixed with dark-coloured blood have the property of rendering it of a florid red ; and it must have appeared that by circulating through its body ils dark colour is restored. As it is capable of being rendered florid by several substances, so it may be rendered dark by several when florid : vital air [oxygen gas] has the power of rendering it florid; but the other vapours, or gases, which have the name of airs, such as fixed air, inflammable air, etc., render it dark. This change is peculiar to the living body, for if arterial blood is taken away, it retains its florid colour, although not in the least exposed to the air.f As it is found dark in the veins, and as it performs some offices in the course of the circulation which perhaps render it unfit for the pur- * [This question was for a long while agitated, many physiologists contending that the blood acquired in its passage through the spleen, omentum, intestines, &c, peculiar qualities which fitted it for the secretion of the bile. However this may be, it certainly is not indispensable. The trunk of the vena portae has been found in several instances to terminate in the inferior cava, instead of branching out into the liver. Mr. Abcrnethy found this in a child about ten months old (Phil. Trans., 1793, p. 59), and Mr. Wilson in a young female (Med. Gaz., viii. 443), the gall-bladder in both cases being perfectly full; and in the last case the hepatic artery increased to a great size. Saunders, Huber, and Lawrence have referred to similar cases.] t [Arterial blood is rendered dark by being placed in the vacuum of an air pump. There appears, therefore, no good reason for believing that any of the effects, relating to change of colour, which take place in the lungs, are peculiar to the living body.]