Cases and observations illustrating inflammatory effusions into the substance of the lungs, particularly as modified by contagious fevers / by William Aitken, M.D.

  • Aitken, William, 1825-1892.
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: Cases and observations illustrating inflammatory effusions into the substance of the lungs, particularly as modified by contagious fevers / by William Aitken, M.D. 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.

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    the lung. Accordingly, the amount of fat in the lung accumulates from the period at which the compound granular cells begin to disintegrate, onwards to complete disintegration of the tis- sue of the lung itself; and this accumulation takes place indepen- dently of the contents of the compound granular cell being composed of fat granules. During foetal life the fat contained in the lungs amounts to 10-18 per cent.; but, after respiration is established, the proportion of fat in the normal condition of the lung never rises to above 6 per cent.* When, however, a portion of lung is rendered impervious to air by disease, the fat accumulates, and becomes, in relation to the whole weight of the lungs, 15-40 or even 50 per cent., according to the amount of pulmonary tissue involved. In this way the amount of fat in the lungs becomes relatively as great as the amount of fat in the liver, which always contains a large proportion. In the normal state, fat is now as- certained to exist in small quantity only as an essential constituent of the nervous tissue, as in the nerves and brain ;-|- and it is only under the following conditions that fat accumulates in the textures of the body. If reference be made to the atomic constitution of fat, as compared with the ingesta and egesta of animals, it shall be found that in every tissue the formation or deposition of fat stands in a definite relation to the respiratory process, depending on the conversion of the carbon of the substances destined for respiration into carbonic acid by combination with oxygen. The abnormal condition, therefore, which causes the deposition of fat in any tissue of the animal body, depends on a disproportion between the quan- tity of carbon and hydrogen in the food, and that of oxygen ab- sorbed by the skin or lungs, the oxygen being deficient. In individuals possessing an abnormal tendency to fatness, the circu- lation is out of proportion with the digestion; and such persons have in general very small lungs.]: And, again, when the lung is diminished for the function of respiration, by any part of its substance becoming the seat of an exuded product, then that part is brought into circumstances analogous to any other tissue of the body, and subject to the same laws in regard to the deposition of fat. The production of fat is always a consequence of a deficient supply of oxygen, for oxygen is absolutely indispensable for the dissipation of the excess of carbon and hydrogen in the food ; but the volume of air in which respiration goes on does not, under the influence of vegetable and animal life, undergo any change ; and as the quantity of fat in the tissues increases when the oxygen absorbed by the lungs and skin in a given time does not suffice to convert into carbonic acid and water the elements of the non- * M. Natalis Guillot, in Gazette Medicale tie Paris, No. 29, 1847. -f- Liebig's Animal Chemistry, 3d ed., p. 94. X Liebig, loc. cit.