Animal Nutrition. 55 



results as those made witli sheep, pigs, geese and ducks, some of 

 which have been reported in the preceding pages; ^ but as the 

 formation of fat from carbohydrates has been established in the case 

 of other animals, it follows that cows also have the same ability, 

 since the nutritive processes are essentially the same in all the 

 higher animals. 

 I The formation of fat from carbohydrates was long considered 

 impossible because no intermediate steps in the transformation 

 were known. Lately, however, it has been found that butyric, 

 capronic and higher solid fatty acids are formed from carbohy- 

 drates in putrefactive processes. We have seen that the fatty 

 acids are readily taken up by the animal system and changed into 

 fats, which may be deposited in the body or oxidized, according 

 to the supply of nutrients and the nutritive condition of the 

 animal. (75) This being true, there is no theoretical difficulty in 

 the way of the formation of the fat of milk from carbohydrates. 

 78. Fat from protein. — It has long been known that fatty acids 

 may be formed from protein substances in putrefactive processes, 

 both in the animal body and elsewhere, and also through oxidizing 

 agents. In certain diseases, especially cases of phosphorus poison- 

 ing, fatty degeneration will occur in the body; the muscles waste 

 and a waxy fat appears in their stead, and is also deposited on the 

 internal organs. In one case the dry matter in the liver of a man 

 who died from phosphorus poisoning contained the enormous 

 amount of 76.8 per cent, of fat. 2 In an experiment by Bauer, ^ 

 a dog was poisoned with phosphorus after having been starved 

 twelve days. It died seven days later. The excretion of ui'ea 

 was quite constant fi-om the fifth to the twelfth day of the experi- 

 ment, amounting to 7.8 grams daily. After the poisoning had 

 begun, the excretion increased until it amounted to 23.9 grams 

 per day, i. e., three times the normal amount. It was ascertained 

 with another dog treated the same way, but kept in a respiration 

 apparatus, that the excretion of carbonic acid and the amount of 

 oxygen taken up decreased one-half after the phosphorus feeding 



^ For a review of the extensive literature on the subject up to August, 

 1881, see B. Schulze, Landw. Jahrb., XI, p. 57. 



* Wolff, Landw. Fiitterungslehre, 1888, p. 44. 



• Zeitschr. f. Biologle, VII, p. 76; Voit, Physiologie, p. 248. 



