HISTORY—CLIMA TOLOGY 



1451 



to receive moisture therefrom, because of its being already suffi- 

 ciently laden with moisture. They also held that tight and heavy 

 clothing, the ingestion of too little water, were minor causes, but 

 they were not sure as to the evil effects of alcohol, and saw no evi- 

 dence in favour of any causal effect due to the actinic rays from the 

 sun; but they discuss the possible action of a poison produced by 

 heat affecting metabohsm. 



In 1918 Shakles made an important series of experiments upon 

 Cercopilhecus monkeys exposed to the sun at Manila. He found that 

 though the sun's rays per s& were not harmful, still unacclimatized 

 monkeys invariably die of heat stroke after an exposure for some 

 time. This helps to prove that the clinical effects of heat stroke 

 can be produced by exposure to the sun as well as by heat in the 

 shade. 



He noted that anything which disturbed heat regulation produced 

 fatal results — for example, a small dose of atropine did so by dis- 

 turbing the loss of heat due to perspiration {vide Chapter IK.). 



He also observed that intestinal toxins lowered the resistance 

 of the experimental monkeys, which is most interesting in view 

 of the prodromal symptoms sometimes experienced by man and 

 referable to the alimentary canal. With reference to man, this 

 observer considers that the regulation of diet in great heat is most 

 important. He further notes that the effects of the tropical sun are 

 exactly the same as that of the Northern United States during 

 certain seasons of the year. 



Climatology. — 'The tropics are the principal seat of the complaint. 

 Of these India appears to be the most important, and in it the Punjab, 

 Sind, and the North-West Provinces are the worst, as can be judged 

 by a reference to their climatology. 



In Ceylon sunstroke is said to be much less common than in India. 

 Thus, in 1903, according to Sir Joseph Fayrer, in statistics given 

 to him by Surgeon-General Sir A. Keogh, there were 303 cases in 

 India among the European troops, with 53 deaths; and in Ceylon 11, 

 with 2 deaths, the total for the British Army for that year being 

 385 cases and 61 deaths. 



In Asia it is well known in the Red Sea, the Persian Gulf, Burma, 

 the Straits Settlements, South China, and Cochin China. In Africa 

 it is met with in all parts of the tropical region. It is common in 

 Mauritius, and is also well known in the United States, Canada, 

 Nova Scotia, New Brunswick, and the West Indies. In South 

 America it is met with in Guiana, Brazil, Peru, and the Argentine. 

 In Australia it has also been recognized, and in Europe in summer. 

 It is, of course, associated with the warm seasons in all countries, 

 and with either very high air temperatures in relatively dry climates, 

 or with not so high temperatures if there is much atmospheric 

 humidity. 



The disease stands in direct relationship to heat-waves, as has 

 been pointed out by Rogers in India and well knov/n in temperate 

 climates. Thus, according to Gauss and Meyer, in July, 1916, the 



