Consumption, and the Breath Rebreathed

Abstract

THIS work is written con amore by an enthusiastic physician, who has satisfied himself of the truth of the theory he advances, and is now desirous of convincing the rest of the world. The theory broached by Dr. MacCormac is that phthisis or pulmonary consumption, as well as tubercle generally, is always and exclusively the result of the breathing of air that has already been vitiated by respiration. It is well known that air that has once passed through the lungs has undergone important changes. Its oxygen is reduced in quantity, a nearly corresponding amount of carbonic acid has been added, and it also contains certain organic compounds the nature of which has not been very satisfactorily determined, but which are undoubtedly of an effete nature, and analogous in their composition to the disintegrated organic compounds eliminated from the body by the other excretory organs. The extremely deleterious action of the re-introduction into the system of the materials discharged by the intestines is now very generally known, from the inquiries that have been instituted into the nature and origin of typhoid fever; and Dr. MacCormac is perfectly justified from analogy in attributing serious results to the re-introduction into the system by the lungs of the air which has once passed through it, and which is consequently charged with decomposing substances. The carbonic acid alone is bad enough, but even if this were removed as fast as formed and replaced by oxygen, while the animal still continues to breathe the air it has already expired, there can be little doubt that it would speedily feel the effects of the other impurities with which expired air is charged. Under ordinary circumstances the only means of avoiding these effects is to permit free access of air to all and every apartment in which man is confined either by day or night; and so far we cordially endorse the views and recommendations of the author of the work before us. But when Dr. MacCormac states that tubercle is exclusively the result of breathing expired air, we think he carries his theory too far. We cannot put aside in the facile manner he adopts the influence of hereditary predisposition, nor the effects of exposure to damp and cold, when combined with insufficient food. Imperfect ventilation is so common that it is almost always associated with the other probable causes of tubercle, and it is difficult to give instances where tubercular consumption has made its appearance whilst perfectly pure air is continually breathed. But, we think, various considerations render Dr. MacCormac's views untenable. We will not refer to Iceland or to the inhabitants of the elevated plains of the Andes, or of the Steppes of Asia—all of which are sad stumbling-blocks in his way—because, as he says, they are so far off, and our facts in regard to the frequency of tubercle in these regions are perhaps not quite satisfactorily ascertained. But we may call attention to the circumstance that the disease is more common in England than in almost any other country—than in France, for example; yet, surely, the hygienic relations in regard to ventilation are superior in England to those existing on the other side of the Channel.

Consumption, and the Breath Rebreathed.

By Henry MacCormac. (London: Longmans, 1872.)