286 ITS BEARING ON MEDICAL PRACTICE. 



illustrate the principles I have attempted to lay down. These diseases 

 are — 



A. Typhus fever. 



B. Cholera asiatica. 

 0. Diabetes mellitus. 



A. Typhus fever. — In typhus fever a prominent symptom is the remark- 

 able elevation of temperature, accompanied by an increased excretion of 

 urea and carbonic acid by the kidneys and lungs, indicating (as no food 

 is taken) an increased morbid metamorphosis of the blood and tissues. 

 The temperature commonly rises to 104° F., representing an increase of 

 upward of 5° F. above the normal temperature. 



If we knew the cause of this increase of temperature, or, rather, of the 

 increased metamorphosis of which it is the sign, we should know the 

 cause of typhus fever, and learn to combat the disease on rational grounds. 

 At present the cause is unknown, and, therefore, the physician is forced 

 to treat the symptoms as they appear, instead of attacking the cause of 

 the disease. Let us examine for a moment the terrible significance of 

 the symptoms. 



Your patient lies for nine or ten days supine, fasting, subdelirious, 

 the picture of weakness and helplessness, and yet this unhappy sufferer 

 actually performs, day by day, an amount of work that might well be 

 envied by the strongest laborer in our land. 



The natural temperature of the interior of the body is 100° F., while 

 the temperature of the corresponding parts in typhus fever is at least 

 105° F. This seems at first sight a small increase — only 5 per cent, of 

 the whole — but it is in reality 2^ times as great as it appears, and 

 actually amounts to 12J per cent., or one-eighth part of the total animal 

 heat ; for the total quantity of heat given out by the heated body is pro- 

 portional (from Newton's law of cooling) to the elevation of its tempera- 

 ture above the temperature of equilibrium, toward which it tends. If 

 we suppose this equilibrium temperature to be 60° F., then the quanti- 

 ties of animal heat given out in typhus fever and in health will be in 

 proportion of 45 to 40, showing that the animal heat of typhus exceeds 

 that of health by one-eighth of its amount. 



We have already seen that the work due to animal heat would lift the 

 body through a vertical height of six miles per day; and it thus appears 

 that an additional amount of work, equivalent to the body lifted through 

 nearly one mile per day, is spent in maintaining its temperature at fever 

 heat. 



If you could place your fever patient at the bottom of a mine twice 

 the depth of the deepest mine in the duchy of Cornwall, and compel the 

 wretched sufferer to climb its ladders into open air, you would subject 

 him to less torture, from muscular exertion, than that which he under- 

 goes at the hand of nature, as he lies before you, helpless, tossing, and 

 delirious, ou his fever couch. 



The treatment of this formidable disease in former times consisted of 



