ON THE DISEASES OF MANKIND. 805 



ever afflicted mankind, have prevailed in tropical 

 Africa, where the temperature is higher during 

 the heat of the day, than in any other part of the 

 globe, and where the atmosphere is filled with 

 putrid effluvia from the decomposition of vege- 

 table matter both of which diminish respira- 

 tion, sanguification, secretion, nutrition, and all 

 the forces of life. Many travellers relate, that 

 when trading caravans are overtaken by the hot 

 simoom from the Great Desert, (which operates 

 like a furnace or heated air bath,) it causes ex- 

 cessive langour, prostration of strength, loss of 

 appetite, nausea, fainting, and sometimes sudden 

 death.* Under such circumstances, the process 

 of respiration is nearly arrested, and the tempe- 

 rature of the solids is raised so nearly to an 

 equilibrium with that of the arterial blood, that 

 the transition of caloric from one to the other, on 

 which the process of nutrition depends, is nearly 

 suspended, and all the energies of life are pro- 

 portionally diminished. 



When the system has been exposed for several 



* To avoid its fatal influence, the Arabs are in the habit of 

 lying down, digging holes in the ground, and applying their nos- 

 trils to the fresh earth. The East India Papers also state, that 

 during the month of June, 1842, the mercury stood at 110 in 

 the shade at Jellalabad, (in lat.26,) and that the British soldiers 

 dug holes under their tents, by which they obtained a temperature 

 of 90. No wonder the beasts of the forest in Africa and southern 

 India, retire during the heat of the day to the thickest shades they 

 can find, or to pools of water, where they lie panting until the 

 cool of the evening comes on. 



