ORIGIN OF FAT OUT OF CARBOHYDRATE 301 



The end stage of the reaction is represented by Hanriot in the 

 equation : 



I C 16 H 31 2 



(Oleo-stearo-palmitin) 

 + 23CO 2 + 26H 2 O. 



Bleibtreu calculates that 270 '06 grm. glucose can form 100 grm. 

 fat, 54-61 grm. water, and 115-45 grm. C0 2 . Rubner calculates 

 that 6 per cent, of the available energy is lost in the chemical 

 work of transmutation. 1 



Respiratory quotients greater than 1 have been observed by 

 Regnault and Reiset and others. Hanriot obtained an R. Q. = T28 

 in man fed on dextrose. Pembrey has observed an average respira- 

 tory quotient of 1*21 in a marmot during the stage of fattening. 

 In rats after a rich meal of carbohydrate he and Spriggs have 

 obtained R. Q. of 1*17. These high quotients are due to increased 

 output of C0 2 , not to decreased intake of 2 . Laulanie has ob- 

 served R. Q. above unity in dogs fed on much bread or sugar. As 

 to the possible seat of this transformation, it is worth noting that 

 Leathes finds that liver pulp, when suspended in Ringer's solution 

 and aerated, forms 10-40 per cent, more fat than it originally 

 contained, and the amount formed is increased by the addition 

 of glycogen. 



The fat formed from carbohydrate seems to contain more 

 stearin and palmitin and less olein. 



In geese fed on potatoes Rosenfeld found the fat put on of higher 

 melting-point and poorer in olein with an iodine number 63, while the 

 iodine number of normal goose fat was 79. He found the same kind 

 of hard fat put on in dogs, rabbits, ducks, and carp when fed on 

 carbohydrates. 



The iodine number of the body fat of various carnivorous 

 animals approaches that of the fat on which they feed. Rosenfeld 

 fed a dog on mutton fat, and then for a month on food in which 

 no fat was given. At the end of this time the body fat had still 



1 " The conversion of the resorbed nutrients of the food into the ingredients 

 of tissue involves profound chemical changes, and we can hardly suppose these 

 take place without some evolution of heat." Johansson, Tigerstedt, &c., compute 

 that 15 per cent, of the total energy of resorbed food is thus spent. 



