On the importance of chemistry to medicine : an introductory address to the medical classes of King's College, delivered October 1, 1845 : with an inaugural lecture at King's College, given October 6, 1845 / by W. A. Miller.
- Miller, William Allen, 1817-1870.
- Date:
- 1845
Licence: Public Domain Mark
Credit: On the importance of chemistry to medicine : an introductory address to the medical classes of King's College, delivered October 1, 1845 : with an inaugural lecture at King's College, given October 6, 1845 / by W. A. Miller. Source: Wellcome Collection.
Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.
10/40 (page 10)
![Three of the excreting glands, from their size and importance, may here be mentioned, viz., the lungs, the kidneys, and the liver. The organ last named appears to be the connecting link between the secernent and excreting glands, as it partakes of the characters of both. The lungs difter from the kidneys and liver in one very remarkable particular, for they do not contain within themselves the agent that effects the transformation and separa- tion of their peculiar secretion. Some texture in the structure of the kidneys and the liver appears to be the immediate agent in producing the changes which the blood undergoes in them, and so long as a free circulation through these glands is main- tained their functions may continue undisturbed. Far different is it with the lungs. The important processes which here occur obviously depend upon the intervention of atmospheric air, which is brought to act u])on the blood in the most complete and favourable manner, owing to the minute state of subdivision in which both are presented to each other in the exquisitely delicate interlacement of air-tubes and blood-vessels of which the lungs consist. This minute division of the blood for the purposes of aeration, is the onl}-^ office which the organ per- forms. The alterations which the blood undergoes within it are, so far as we can distinguish, producible out of the body, by simply exposing it to the air, and are of a purely chemical nature. No secretion in a liquid form is here separated. The products are entirely gaseous. The striking nature of the changes thus effected, the sudden alteration of colour from the dark purple which the blood has on its entrance, to the vermilion which it possesses on its exit from the lungs, the removal of a large portion of the oxygen of the air, and its replacement by a bulk of carbonic acid nearly equal to itself, the large amount of aqueous vapour thus constantly exhaled, together with the precision of which the analysis of the expired air is susceptible, not less than the vital importance of the function of respiration, early fixed the attention of chemists. Numerous careful experiments were made by different individuals, though with widely differing results, in order to determine the relative proportion of matter thus re- moved from the system, the limits within which it varied, and the circumstances under which such variations took place. We have, in consequence been put in possession of more com- plete information upon this subject than upon any other point of chemical physiology. Yet this completeness is merely com- parative, for many enquiries have still to be prosecuted. The influence of climate on the production of carbonic acid, the variations which this substance undergoes in quantity from modi- fications of diet, both in the arctic and tropical climates, tlic](https://iiif.wellcomecollection.org/image/b21472865_0010.jp2/full/800%2C/0/default.jpg)
