FORMATION OF FATS FROM CARBOHYDRATES. 537 



with foods especially rich in carbohydrates LAWES and GILBERT, SOXH- 



LET, TSCHERWINSKY, MEISSL, and STROMER (on pigs), B. SCHULTZE, 



CHANIEWSKI, E. VOIT and C. LEHMANN (on geese), I. MUNK and RUBNER 

 and LUMMERT 1 (on dogs) apparently prove 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 complicated carbon chains as the fats, the formation 

 of fat from carbohydrates must consist of a synthesis, in which the 

 group CHOH is converted into CH 2 ; hence a reduction must occur. 



After feeding with very large quantities of carbohydrates the rela- 

 tion between the inspired oxygen and the expired carbon dioxide, i.e., the 



CO 



respiratory quotient - p, was found greater than 1 in certain cases (HAN- 

 RIOT and RICHET, BLEIBTREU, KAUFMANN, LAULANIE 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 

 alimentation a nutritive substance of great importance in the develop- 

 ment of heat and vital force, which substance, on insufficient nutrition, 

 is given up as may be needed. On account of their low conducting 

 power, the fatty tissues become of great importance in regulating the 

 loss of heat from the body. They also serve to fill cavities and act as 

 a protection and support to certain internal organs. 



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, Sitz- 

 ungsber. 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 China, et de Phys. (6), 22; Bleibtreu, Pfluger's 

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



3 Amer. Journ. of Physiol., 6. 



