600 A MANUAL OF PHYSIOLOGY 



venting the free loss of heat for a sufficient time (so-called 

 physiological fever), the destruction of protein is augmented. 

 A fasting dog whose temperature was increased to 40 or 41 C. 

 for twelve hours eliminated 37 per cent, more nitrogen than when 

 the body-temperature was normal. But this increase in the 

 protein metabolism could be entirely prevented by giving the 

 animal a sufficient amount of carbo-hydrate. Similar results 

 have been obtained in man. The carbon dioxide excretion and 

 oxygen absorption are, of course, also markedly increased. But the 

 increase in the nitrogen excretion is often much greater in fever 

 than any increase which can be brought about by artificially 

 raising the temperature of a healthy individual by means of hot 

 baths. A typhoid patient was found to lose 10-8 grammes of 

 nitrogen a day (corresponding to 318 grammes of muscle) during 

 eight days of fever (F. Miiller) . A portion of the loss of nitrogen 

 on the routine fever regimen may be due to the fact that the 

 ordinary typhoid patient is really on a semi-starvation diet, 

 the heat-equivalent of which is not much more than half his 

 heat-production. Yet it has not been found possible to com- 

 pletely prevent the loss of nitrogen by putting the fever patient 

 on a diet rich^ in protein, or on a diet containing a moderate 

 amount of protein with a large quantity of fat and carbo- 

 hydrate, even when the total heat-value of the diet is much in 

 excess of the 32 or 33 calories per kilo of body-weight which 

 corresponds to the heat-production of a resting man. Another 

 suggestive fact is that the excessive excretion of nitrogen does 

 not run parallel with the rise of temperature in fever, but is 

 often most marked after the crisis. During the stage of defer- 

 vescence an enormous amount of urea is sometimes given off. 

 In a case of typhus, in the mixed urine of the third and fourth 

 days after the crisis, no less than 160 grammes of urea was 

 found (Naunyn), or nearly three times the normal amount for 

 a man on full diet. Again, when fever is caused by the injection 

 of bacteria or their products, the increase in the carbon dioxide 

 eliminated and oxygen consumed occurs even when the tem- 

 perature is prevented from rising by cold baths. It seems 

 perfectly clear, then, that the increase of metabolism is, in many 

 cases at least, a primary phenomenon of fever. Its course and 

 incidence, falling as it does so largely upon the proteins, the 

 steady loss of tissue nitrogen, and the inability of the tissues to 

 recoup their losses from the protein of the food or to shield 

 their own protein by burning more carbo-hydrate or fat, all 

 suggest that the cells are poisoned by toxic products of the 

 infective process. The poisoned bioplasm falls an easy prey 

 to the hydrolyzing and oxidizing agents always present in the 

 tissues. It breaks down more rapidly and builds itself up more 



