172 THE POPULAR SCIENCE MONTHLY. 



great fatigue or over-exertion, or when there is depression of vital 

 power from any cause during exposure to a high temperature. There 

 is depression of nerve-force and of muscular power ; the skin is pale, 

 cold, and moist, the pulse feeble. Death may occur in this state from 

 failure of the heart ; but complete recovery more frequently occurs. 

 Asphyxia and apnoea (stoppage of the breath) may come on after pre- 

 monitory symptoms of depression and weakness, during exposure of 

 the head and spine to the direct rays of a powerful sun, when the 

 atmosphere is much heated, and the nervous energy is depressed by 

 over-fatigue, illness, or dissipation. The brain and respiratory nerve- 

 centers are overwhelmed by the sudden rise of their temperature, and 

 respiration and circulation fail. 



Recovery, though frequently complete, is sometimes tedious and 

 occasionally imperfect, ending in serious impairment of health or in- 

 tellect. 



The symptoms of this form of sunstroke are those of sudden and 

 violent derangement of the nerve-centers, unconsciousness, cold shivers, 

 feeble pulse ; all the signs of depression, terminating in death by shock ; 

 or fatal reaction may result with a variety of conditions pointing to 

 injury to the cerebro-spinal system. In another class of cases there is 

 ardent fever, the body generally, including the nerve-centers, is heated 

 intensely ; this may occur quite independently of the direct action of 

 the sun's rays. It comes on frequently at night, or in the shade, in a 

 building or tent, especially in persons who are depressed by fatigue, 

 bad air, overfeeding, alcoholic stimulants and the consequent depres- 

 sion, want of rest, illness, and notably when the air is impure from 

 overcrowding, or from insufficiency of cubic space. 



The temperature of the body may rise to 108-110 ; respiration 

 and circulation fail ; there are hurried, gasping respiration, great rest- 

 lessness ; pungently hot skin, sometimes dry, occasionally moist. The 

 pulse varies ; in some it is full and laboring, in others quick and jerk- 

 ing ; the head, face, and neck are livid and congested ; the carotid 

 pulsation is very perceptible ; the pupils, at first contracted, dilate 

 widely before death. Coma, stertor, delirium, convulsions frequently 

 epileptiform in character, with relaxation of sphincter, and suppres- 

 sion of urine these are the precursors of death by asphyxia, and it 

 may be that there is cerebral haemorrhage. 



Such are the cases to which the term heat-apoplexy is given ; and a 

 large proportion of the fatal attacks among Europeans in India are so 

 caused. Recovery may partially occur, to be followed by relapse and 

 death, or secondary consequences, the result of tissue-change, may 

 destroy life or impair health and intellect at a later period. The pre- 

 monitory symptoms of this form of the disease may appear some hours 

 or even days before the dangerous condition just described supervenes. 

 There may be general malaise, disordered secretions, profuse and fre- 

 quent micturition, restlessness, insomnia (sleeplessness), apprehension 



