The physiologists who see in the animal economy only one element, do not pretend to say, by this, that man is formed of a unique substance, diversely modified, but they wish to inculcate, that among the elements that enter into the constitution of man, there is one which predominates over the rest, by its energy or its activity, and concurs in a preponderating, if not exclusive manner, to the production of physiological and pathological phenomena. To establish the unity of the active forces of nature, has been the dream of many physiologists and physicians ; but up to this time, all the hypotheses conceived to this end, have been Utopian.
The Hippocratic collection includes two books in which the doctrine of a " single clement " reigns. One, a treatise on embryology, is entitled, “on the Nature of the Child," and is well executed and complete enough for that epoch. It seems to be the conclusion of the book on Generation. The other is a very short treatise on general pathology, which has for a title, " On Air." The air, breath, or as the Greeks call it, pneuma, plays the principal part in the two treatises, but its influence is considered in a much less clear and exclusive manner in the first than in the second.
We read in the latter as follows : " An important thing to discover, is the cause of diseases - the origin, the source of the evils that are engendered in the body. Whoever can comprehend the cause of a disease will be capable of curing it, by employing a remedy which is the opposite of the evil from its commencement."
After having shown the necessity of going back to the cause of diseases, to effect their cure, the author continues thus : " The nature of all affections is the same ; they differ only in relation to their seat. 1 think that they only show themselves under so many different forms on account of the great diversity of parts where the disease is located. Their essence is one, and so is the cause that produces them. But what is this cause ? This is what I will endeavor to explain."
" The body of man is nourished by three things - food, drink, and air ; he eats, drinks, and breathes. The air in the body is called spirit, or breath ; that external to the body is called wind. It is the breath that produces the greatest phenomena, and its influence merits all our attention. Nothing can be done without air ; it is everywhere present ; it fills the immense interval that separates the earth from the heavens ; it is the food of fire ; how could fire subsist without it ? It could not exist long. It is not difficult to conceive that the interior of the sea participates equally in its benefits. The animals that swim there could not exist without respiration. There is nothing, in fine, that does not feel its effects. (Traité des Vents, Â§ 1. Gardeil)
The author examines next, more particularly, the influence of the breath for the support of human life. He observes that its influence is uninterrupted ; that man may abstain more easily from drinking and eating than breathing, from which he concludes that, air, being the thing most indispensable to the human economy, is also that which occasions in it the gravest and most frequent disorders. " Thus I can conceive that the principle cause of disease is in the air. This may be too strong or too feeble, or be precipitated in the body, or enter it charged with miasms. It suffices to have established this as a general principle ; then, by descending into details, I will explain how each disease, in particular, proceeds from the breath or air."
Because the air is one of the most necessary things to life, and if you please, the most necessary, does it inevitably follow that it is the unique source, or at least the most common source of diseases? This does not appear to me to be demonstrated. But I do not insist on this general objection ; it is particularly in the face of facts or detailed observation, that our systems are demolished. Let us see how the pneumatic system stands this test ; this will dispense with the necessity of longer argument.
The fever which supervenes after an improper diet, is explained, according to this system, as follows : " Much food introduces necessarily much air ; for the air enters more or less into the body, in proportion to the quantity swallowed of liquids or solids. For this reason, wind is belched up after eating or drinking too much. The air being thus compressed, bursts the little cells in which it is .contained, and mounts upward. The body swells, by the excess of air, and the food remains in the stomach, prevented by the great quantity of air from passing into the intestines. The air is diffused into all parts of the body, and cools even the most sanguineous portions ; it goes even to the origin and source of the blood, whence it is spread everywhere, and produces the shivering that precedes fevers. The more air, the more refrigeration, and the greater the shivering."
I will limit here my quotation ; the reader is, I think, sufficiently edified on the value of this pathological system, by the explanation which is offered for the first symptoms of fever. Let him guard himself, nevertheless, from sentiments of pity toward the ancients, on account of the theoretical errors he discovers in their writings ; let him remember that in regard to theory, even the most eminent moderns are not exempt from illusions, which will, in a future day, excite the smiles of those who shall look upon them in another and superior light to ours. The deceptions of antique science should render us circumspect, and cause us to accept with reserve the assertions of cotemporaneous science.
From History of Medicine by P.V. Renouard M.D.