426 SCIENCE PROGRESS 



ward by Burge (19 14) with reference to the protection of the 

 mucous membrane of the stomach and intestine. The mucous 

 membranes of the intestinal tract possess intensive oxidation 

 processes, and in virtue of the nascent oxygen which is known 

 to destroy pepsin and trypsin, the autolytic enzymes are held 

 in check during life. The same observer in 191 7 found that in 

 animals fed on thyroid there was an increase in catalase of the 

 blood, of the skeletal muscles, and the heart, and consequently 

 an increase in body oxidation processes. There was, however, 

 a decrease in catalase of other organs of the body, and in 

 these an increased autolysis was noted. There is, then, in 

 the work mentioned above considerable evidence regarding 

 the regulation of enzyme activity and the protection of the 

 organism by catalase. 



Catalase is now shown to bear a direct relation to food. 

 Burge, Neill and Ashman (19 16) exposed the livers of dogs, 

 took samples of blood issuing from the liver, and compared it 

 with blood from other veins. They found that catalase was 

 increased by the ingestion of starchy foods, more so by the 

 ingestion of sugars, while an even greater increase was caused 

 by food products, especially protein food. An increase was also 

 caused by the fats of olive oil and bacon. Coffee, cocoa, tea 

 and milk, however, did not make any appreciable difference, 

 but chocolate caused a definite increase. Ripe fruit caused an 

 increase — presumably due to its sugar — ^while unripe fruit did 

 not. 



These observers also claimed to have obtained an increase 

 of catalase by stimulation of the splanchnic nerves. They 

 found also that in severe fatigue the catalase of the 

 tissues was used up, and suggested that herein lay the cause 

 of the non-oxidation of lactic acid which is known to accumu- 

 late in such cases. Burge (191 6) showed that the amount of 

 catalase varied directly according to the amount of work done, 

 and that warm-blooded animals, in whose bodies more oxida- 

 tion took place, had more than cold-blooded animals. This 

 latter fact confirmed the work of earlier observers. W. E. 

 Burge and E. L. Burge (191 7) showed that there was an increase 

 of catalase in the liver of cats which had been subjected to 

 fright immediately before death. 



Some of these results were confirmed by Burnet (191 8), who 

 showed that accelerated muscle activity was due to an intense 

 secretion from the liver, which could be stimulated by food, 

 especially protein. He noted also that the extirpated liver 

 liberated for two hours catalase, presumably due to dextrin 

 formed from the glycogen. 



The relationship between catalase and the production of 

 shock was brought to notice by Burge and Neill in 191 8. They 



