6 



Mr. C. H. KeUaway. The Effect of Certain 



by us,* and its actual fixation for any given H"*" concentration, as shown 

 to- day, constitute, as will readily be understood, but different expressions of 

 the same phenomenon, being a consequence the one of the other. 



The bearing of these results on the general law of the independence of the 

 optimum temperature of an enzyme of the concentration of the latter, will 

 not have escaped notice. We see in them but instances of the working of 

 this law, which they throw a new light upon, in indicating that in its original 

 statement it is stated too briefly ,t and now requires amplification. In conse- 

 quence, re-stated, it hecomes : the optimum temperature of any ferment, or 

 ferment function, occurring in a given enzymic preparation is independent of 

 the concentration of the enzyme, the duration of the action and the chemical 

 reaction — or H"*" concentration — of the medium being constant. 



The question asked at the beginning of the investigation thus finds itself 

 answered ; and, if in a manner different from the limited sense in which it 

 was formulated, still the answer is none the less instructive, in the light 

 which it throws on a seneral aspect of the mechanism of enzyme action. 



The Effect of Certain Dietary Deficiencies on the Suprarenal 



Glands. 



By C. H. Kellaway, Foulerton Student of the Eoyal Society. 

 (Communicated by W. B. Hardy, Sec.R.S. Eeceived August 13, 1920.) 



[Plate 1.] 



During recent years McCarrison (1919 a, h, and 1920) has published a 

 series of important papers dealing with the effect of deficient diets on the 

 various organs of the body. One very striking result which he has described 

 was a great enlargement of the suprarenal glands, with pronounced increase in 

 their content of adrenaline, in pigeons fed on polished rice and suffering from 

 the consequent polyneuritis. McCarrison's experience led him to put forward 

 the tentative suggestion, that the increased content of adrenaline might be 

 significant of increased output of adrenaline during the development of the 

 disease, and that this might account for the occurrence of oedema both in 

 experimental polyneuritis produced in pigeons and in the wet form of human 



* Arthur Compton, 'Eoy. Soc. Proc.,' B, vol. 88, pp. 408-417 (1915). 

 + Arthur Compton, 'Roy. Soc. Proc.,' B, 87, pp. 245-254 (1914); 'Ann. Inst. Past.,' 

 vol. 28, pp. 866-878 (1914). 



