This infiltration of fat may take place under pathological as well as physiological conditions. It is apparent that those causes which check oxidation are likely also to prevent the consumption of fat, and it is well known that the destructive processes in the lung, grouped under the term pulmonary consumption, accomplish this result. Something more, however, is necessary than the obliteration of pulmonary blood-vessels and the destruction of an aërating surface. There may be, as in emphysema of the lung, a diminished respiratory and vascular surface, yet evidences of fatty infiltration, particularly of the liver, are wanting. It seems probable that the constant anæmia, with the loss of the blood-corpuscles, of pulmonary phthisis is an important additional factor in checking oxidation in this disease. This factor, it is needless to say, is not a necessary occurrence in pulmonary emphysema. Litten[31] has shown that when certain animals are exposed to high temperatures the appearances of fatty infiltration and degeneration are present in various organs of the body. He attributes the fatty degeneration to a direct poisoning of the red blood-corpuscles and a resulting diminution of the oxidizing processes. [Footnote 31: _Virchow's Archiv_, 1877, lxx. 10.] It is universally admitted that in chronic alcoholism a fatty liver is frequently met with, even in the absence of those chronic interstitial tissue-changes usually characterized under the name cirrhosis. Alcohol is known to check the reception of oxygen and the elimination of carbonic acid, and, whatever other disturbance of cell-activity it may produce, its effect in favoring the accumulation of fat is directly attributable, in part at least, to this disturbance of oxidation. In those conditions known as cachexiæ, the constant accompaniment of progressive and wasting diseases, as cancer, leucæmia, chronic dysentery, {78} etc., a fatty infiltration, particularly of the liver, is a frequent accompaniment. A cachexia is dependent upon a complex series of processes, many of which tend to check oxidation, and in this respect is to be grouped with the conditions previously mentioned. That the associated fatty infiltration is intimately connected with the deficient oxidation is not to be doubted, although the agents producing this deficiency may vary in detail.