5 oo THE POPULAR SCIENCE MONTHLY. 



the germs of disease in the excreta of the sick, and in both ways favors 

 the spread of contagion. 



Its direct action upon the person becomes most apparent when 

 some of the functions are going wrong. When the body is healthy, 

 and proper precautions are taken in its management, there is little to 

 fear from exposure to heat. Observers in tropical countries tell us that 

 excessive heats are borne with impunity by the healthy, and that it is 

 mostly those who are either temporarily or chronically out of order 

 that eventually suffer. Not that the body can bear unlimited exposure 

 to great heat, any more than it can endure continuous exertion, but 

 that it is capable of maintaining itself under even excessive heat, if 

 the exposure is not too prolonged. When its powers are impaired by 

 some local or constitutional complaint, however, and it is less able to 

 do the extra work which the influence of excessive heat imposes, then 

 is the time when even slight exposure may be followed by the most 

 serious consequences. 



Authors describe several forms of acute disease that are traceable 

 to heat as the exciting cause, but, as all of these partake more or less 

 of the nature of sunstroke, and as we are writing for the public rather 

 than the physician, it is not necessary here to go into their distinguish- 

 ing features. Sunstroke, or the disease hitherto passing under that 

 name, though known since early times, is even yet not well understood. 

 Up to within a few years, it was believed by patient and physician 

 alike that, to produce it, the body, and especially the head, must be 

 exposed to the direct rays of the sun. There is now abundance of 

 proof to the contrary. In his admirable little work, entitled " Ther- 

 mic Fever, or Sunstroke," Dr. H. C. Wood quotes the records of its 

 occurrence in barracks, hospitals, and tents, and not infrequently in 

 the night-time, in many cases without immediate previous exposure 

 to the sun. According to Dr. Bonnyman, as cited by Dr. Wood, 

 " By far the greater number of cases that yearly occur in India are of 

 men who have not been exposed to the sun. It is not unusual for men 

 to go to bed in apparent health, and to be seized during the night ; 

 and patients in hospitals, who have been confined to bed for days pre- 

 viously, are frequently the subjects of attack." Dr. Swift testifies to 

 its production by exposure to artificial heat, eleven cases treated by 

 him having been attacked in the laundry of an hotel ; while several others 

 occurred in sugar-refineries. Dr. Wood mentions a case of his own, 

 which also originated in a sugar-refinery. Dr. Maclean, in the second 

 volume of Reynolds's " System of Medicine," quotes M. Boudin to the 

 effect that one hundred cases of sunstroke occurred on the French 

 man-of-war Duguesne at Rio Janeiro, most of them at night while 

 the men were lying in their bunks. Much more of similar import 

 might be offered, but enough has been said to show that it is great 

 heat which precipitates the attack, and that it makes little differ- 

 ence whether this come from exposure to the direct rays of the sun, 



