FORMATION OF FATS. 563 



proteins, but rather a synthesis from primarily formed cleavage products 

 of proteins which are poor in carbon. 



The formation of fat from carbohydrates in the animal body 'was 

 first suggested by LIEBIG. This was opposed for some time, and until 

 lately it was the general opinion that a direct formation of fat from 

 carbohydrates not only had not been proved, but also that it was 

 improbable. The undoubtedly great influence of the carbohydrates on 

 the formation of fat as observed and proved by LIEBIG was explained 

 by the statement, that the carbohydrates were consumed instead of 

 the absorbed fat or that derived from the proteins, hence they have a 

 sparing action on the fat. By means of a series of nutrition experiments l 

 with different animals, with foods especially rich in carbohydrates it has 

 been apparently proved that a direct formation of fat from carbohydrates 

 does actually occur. The processes by which this formation takes place 

 are still unknown. As the carbohydrates do not contain such com- 

 plicated carbon chains as the fats, the formation of fat from carbohydrates 

 must consist of a synthesis, in which the group CHOH is converted into 

 CH2,' hence a reduction must occur. 



After feeding with very large quantities of carbohydrates the relation between 

 the inspired oxygen and the expired carbon dioxide, i.e., the respiratory quotient 

 CO 

 -Q^-, was found greater than 1 in certain cases (HANRIOT and RICHET, BLEIBTREU, 



KAUFMANN, LAULANI 2 ). This is explained by the assumption that the fat 

 is formed from the carbohydrate by a cleavage setting free carbon dioxide and water 

 without taking up oxygen. This increase in the respiratory quotient also depends 

 in part on the increased combustion of the carbohydrate. 



When food contains an excess of fat, the superfluous amount is stored 

 up in the fatty tissue, and on partaking of food deficient in fat this 

 accumulation is quickly exhausted; and it is very probable that the 

 lipase is of importance here, as LOEVENHART S has found that all over 

 the body where fat is deposited in large amounts lipase also occurs in 

 considerable amounts. There is perhaps not one of the various tissues 

 that decreases so much in starvation as the fatty tissue. The organism, 

 then, possesses in this tissue a depot where there is stored, during proper 



1 Lawes and Gilbert, Phil. Transactions, 1859, part 2; Soxhlet, see Maly's Jahresber., 

 11, 51; Tscherwinsky, Landwirthsch. Versuchsstaat, 29 (cited from Maly's Jahresber., 

 13); Meissl and Stromer, Wien. Sitzungsber., 88, Abt. 3; Schultze, Maly's 

 Jahresber., 11, 47; Chaniewski, Zeitschr. f. Biologic, 20; Voit and Lehmann, see C. 

 v. Voit, Sitzungsber, d. k. bayer. Akad. d. Wissensch., 1885; I. Munk, Virchow's Arch., 

 101; Rubner, Zeitschr. f. Biologic, 22; Lummert, Pfliiger's Arch., 71. 



2 Hanriot and Richet, Annal. de Chim. et de Phys. (6), 22; Bleibtreu, Pfliiger's 

 Arch., 56 and 85; Kaufmann, Arch, de Physiol. (5), 8; Laulanie, ibid., 791. 



* Amer. Journ. of Physiol., 6. 



