V FEVER 207 



warmer summer ; and all food is, sooner or later, oxidised 

 in the body and during this oxidation gives rise to I; eat. 

 There are reasons for supposing that within certain limits 

 altered production of heat plays a part in keeping the tem- 

 perature of the body constant. 



All the functions of the body which we have so far 

 studied have been seen to be under the guidance of nervous 

 impulses. We may therefore suppose that the production 

 of heat will be no exception to the rule, and indeed there 

 are reasons, based largely on experiment and partly on 

 the phenomena of certain diseases, which justify this view. 

 More than this we must not say. 



14. The Temperature of Fever.— The condition to 

 which the name of fever is given is characterised essen- 

 tially by the temperature of the body being higher than is 

 usual in health. Thus it may rise to as much as 41 C. 

 (105'8'F.) or occasionally even above this point, and 

 there has been much dispute as to how this high tempera- 

 ture arises. By many it is regarded simply as the outcome 

 of a disturbance of the mechanism by which heat is lost to 

 the body, some diminution in loss of heat leading naturally 

 to a rise of temperature ; and probably, this is the most 

 common cause of the rise of temperature. But on the 

 other hand direct measurement shows that a fevered 

 person often gives off nwre heat th<i7i usual and at the same 

 time uses up more oxygen and produces more carbonic 

 acid and urea than is usual. In such cases there is no 

 doubt that the abnormally high temperature is largely due 

 to an over-production of heat. 



15. The Liver. — The liver is a constant source both of 

 loss, and, in a sense, of gain, to the blood which passes 

 through it. It gives rise to loss, because it secretes a 

 peculiar fluid, the bile, from the blood, and throws that 

 fluid into the intestine. It is also in another way a 

 source of loss because it elaborates from the blood passing 

 through it a substance called glycogen, which is stored 

 up bometiuies in large, sometimes in small, quantities in 



