INCREASE OF REACTION VELOCITY 613 



is neither greater nor less than that in inhabitants of the 

 temperate zones, 8 yet their body temperature is also con- 

 stant; but from the effects of hot baths (including hot air 

 baths and radiant light baths) by which the temperature of 

 the body is raised to 38-39.5 C., a very distinct and some- 

 times a very important increase of metabolism is attained. 9 

 In an individual suffering from ichthyosis (fish-scale dis- 

 ease), in which affection the output of water through the 

 sweat glands and in connection therewith the heat regu- 

 lation as well, are apparently decidedly diminished by 

 simple sojourn in a well-heated room (in spite of the fact 

 that the body temperature never exceeded 39 C.) the 

 exchange was increased to double the normal. 



It therefore seems quite plausible that if the body tem- 

 perature is raised by any single cause this temperature 

 accession in itself drives the exchange up. Friedrich 

 Kraus 10 says definitely in this connection that, if from the 

 gross amount of oxygen requirement found in human beings 

 with fever there be subtracted the amount due to grossly 

 visible muscular movements and besides the excess due to 

 the increased fever heat itself, a neat amount, not very 

 important in the average, will remain. Increase in the com- 

 bustion processes can be safely said not to be the cause of 

 fever ; and in fact one would hesitate in a given case to class 

 this as one of the characteristic features of fever, and would 

 be forced to acknowledge that excessive muscular exertion, 

 in spite of the fact that it raises the gas exchange to a 

 multiple of the normal, leaves the individual temperature 

 of the healthy body at the normal level. 



8 According to Eykmann, Aron, and others. 



'Observations of W. Winternitz and O. PospiscMl, H. Winternitz, H. 

 Salomon, Linser and Schmidt: Literature: A. Lowy, 1. c., pp. 212-214. Accord- 

 ing to recent experiments of H. Murschhauser ( Schlossmann's Clinic, Diissel- 

 dorf), Zeitschr. f. physiol. Chem., 79, 301, 1912, a long-continued exposure to 

 external temperatures of -f 5 in the first place and of +35 in the second 

 place need not give rise to any important change in the metabolism provided 

 the body temperature is not altered. Cf . also J. Ignatius, L. Lund and O. Warri 

 (Helsingfors), Skandin. Arch., 20, 226, 1909. 



10 F. Kraus, I.e., p. 628. 



