72 RESPIRATORY EXCHANGE OF ANIMALS AND MAN 



small amounts (20 to 25 gr.) of certain amino acids given per os to dogs 

 brought about an increased heat production lasting several hours. 

 The increase found was very considerable after glycocoll (from 64*8 to 

 857 Cal. fn a 4-hour period), less after alanine (64*8 to 77*4), slight only 

 after tyrosine and leucine, and altogether wanting after glutaminic acid. 

 The increase in metabolism fell short in every case of the calorific value 

 of the amount of amino acid given, but was considerably in excess of 

 the amount catabolized as determined by the simultaneous increase in 

 urinary nitrogen. Lusk concludes that the amino acids act by stimu- 

 lating the catabolic activity of the tissues, but the inference, though very 

 probable, does not appear to the writer as conclusive, especially 

 because the nitrogen of the urine is not in short periods a reliable 

 index of the nitrogen metabolism. 



The effects of glycocoll have lately been studied by Wolff and 

 Hele [1914] working on decerebrate dogs. They have administered 

 glycocoll both per os (three experiments) and intravenously in saline 

 (three experiments). By the first method of application they find no 

 effect in two experiments and a slight and doubtful one in the third. 

 After the intravenous administration there is in every case a distinct 

 rise in metabolism which may, however, be due partly and perhaps 

 chiefly to the saline (see above, p. 70). 



Urea. Tangl [1911] found a slight increase in metabolism after 

 injection of urea solutions, but the reality of this appears doubtful, the 

 more so as Lusk and Riche [1912, i] saw no effect after administration 

 of urea to dogs per os. 



Phlorizin. According to experiments by Belak [191 2] on curarized 

 dogs phlorizin should produce a very slight increase in standard meta- 

 bolism irrespective of the increased work of the kidneys. The con- 

 clusion is not, however, warranted by the numerical results of the 

 experiments. 



Adrenaline was found by Hari [191 2] to diminish the respiratory ex- 

 change, especially the oxygen consumption, in curarized dogs. Hari 

 thinks that this may be due to a deficient circulation and consequent 

 oxygen lack. 



Baths. Winternitz[i9O2]found that saline baths had no influence 

 upon the standard metabolism of men. An increase of 10 to 12 per 

 cent, was produced by carbonic acid baths (i per cent, saline saturated 

 with CO 2 ) and a still greater by carbonic acid in 2 to 3 per cent, saline. 

 A mustard bath (200 to 700 gr. mustard in water) of 60 minutes' dura- 

 tion increased the metabolism 2 5 per cent, and the exchange remained 



