Volume 1
The physiological anatomy and physiology of man / by Robert Bentley Todd and William Bowman.
- Date:
- 1845-1856
Licence: Public Domain Mark
Credit: The physiological anatomy and physiology of man / by Robert Bentley Todd and William Bowman. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
25/476
![IXTROI). ] HYPOTHESES. combine together only in certain quantities, or in multiples of them ; that each body has its proper combining quantity, and that it never enters into combination except in that quantity, or some multiple of it. This is an ultimate fact, ascertained by numerous experiments, and indicates the law, which is so important in che- mistry, that bodies unite with each other in their combining pro- portions only, or in multiples of them, and in no intermediate proportions. And this, again, has led to the beautiful generaliza- tion of Dalton, that the ultimate atoms of bodies are their respective combining quantities, and bear to each other the same proportion ias their combining equivalents do. Or, to take an example from the science which is to form the subject of the following pages. The function of respiration in animals is a very complex proees-, respecting the nature of which many unsatisfactory hypotheses had been formed, owing to the obscurity in which many of the phenomena, immediately or remotely connected with it, were involved. Until the law of the, diffusion of gases, and of the permeability of membranes bv them, had been developed, and until it had been shewn that car- bonic acid is held in solution in venous blood, no theory of respira- tion could be framed adequate to explain all the phenomena. It is iiiow proved that, in this process, a true interchange of gases takes place through the coats of the pulmonary blood-vessels, tin* oxygen of the air abstracting and occupying the place of the carbonic acid of the blood. An admirable example is thus afforded of a most impor- tant vital process taking place in obedience to a purely physical law. Living objects are those which properly belong to the science of Physiology. These are strongly contrasted with the inanimate bodies (which have never lived), to which other branches of natural science refer. At the same time, there are many points of re- semblance between them; and as both owe their origin to the same Creative mandate, and are reducible (as will be seen by-and- by) to the same elementary constituents, so they are subject in a great degree to the same physical law's, and are to be investigated according to the same principles of philosophical inquiry. \Ve propose, in the first place, to compare living, or organized bodies, with inanimate, mineral, or unorganized bodies, and to ex- plain what is meant by the term Life. Secondly, to review briefly, and with reference to their leading distinctions, the phenomena of the vegetable and animal kingdoms. Thirdly, to point out the value of a knowledge of Physiology, especially that of Man, in relation to medicine, and to explain the best mode of pursuing it.](https://iiif.wellcomecollection.org/image/b28043327_0001_0025.jp2/full/800%2C/0/default.jpg)
