706 ANIMAL HEAT 



was present. All these observations lend support to the famous 

 * retention ' theory of Traube. It has been suggested that the 

 significance of the increased action of the cutaneous vaso-constrictor 

 mechanism in typhoid fever is that the peripheral vaso-constriction 

 is a compensatory arrangement which secures for the organs mainly 

 suffering from the infective process an increased flow of blood to 

 combat the infection. On this hypothesis the rise of temperature 

 in so far as it depends upon diminished loss of heat is a secondary 

 phenomenon inevitably following the redistribution of the blood, 

 and unavoidable except by a corresponding diminution in the total 

 metabolism. In the great majority of cases the production of heat 

 is also increased, on the average by 20 to 30 per cent, of the normal 

 production of a resting man. The increase may be much greater 

 during the chill which ushers in so many infections on account of 

 the muscular contractions in shivering. During the period of rising 

 temperature the production of heat is not necessarily increased. 

 At the height of the fever there is often, though apparently not 

 always, an increase in the heat-production. After the crisis, while 

 the fever is subsiding, the rate at which heat is lost rises sharply. 

 As to the explanation of the increase of metabolism in fever, 

 and especially of the increased metabolism of tissue-protein, 

 various views have been held. Some have gone so far as to say 

 that the increase is merely the consequence, not the cause, of 

 the rise of temperature. But the rebutting evidence which has 

 been brought against this view is strong and, indeed, overwhelming. 

 It is perfectly true that, when the temperature of the body is 

 artificially raised by preventing 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 cf 

 which is not much more than half his heat-production. Yet it 

 has not been found possible to completely prevent the loss of 



