810 ALL PLAGUES ARE 



as the yellow fever has done in New York, 

 Philadelphia, Baltimore, and will shortly do in 

 New Orleans. All other things, however, being 

 equal, the mortality from fever is greater in 

 tropical than in warm climates, where it is more 

 prevalent and fatal than in the middle and higher 

 latitudes.* Nor is it less certain, that nearly all 

 the plagues which have desolated Europe, from 

 those of Athens and Rome, down to the 17th 

 century, including the late epidemic cholera, pre- 

 vailed chiefly during the latter part of summer 

 and beginning of autumn, or until arrested by 

 frost, which puts an end to all epidemic fevers, 

 if we except typhus, a disease that prevails at 

 all seasons among the poor, ill fed, and badly 

 clothed inhabitants of large towns, and filthy or 

 crowded dwellings. 



Again ; the continued form of fever predomi- 

 nates in tropical and warm climates, but remit- 

 tents and intermittents in the higher latitudes, 

 where they prevail chiefly during warm weather, 

 and are arrested by frost. Nor can there be a 

 rational doubt, that all the varieties of fever are 

 different forms of one and the same disease, 



* Dr. Archibald Smith informs us, that the black cattle of Peru 

 and other elevated portions of South America, cannot endure the 

 climate of the low and burning plains near the coast, where, like 

 the human species, they die in great numbers from fever, which is 

 more malignant when they are fat, than lean. Ashmun states in 

 his Diary, that at Liberia, in tropical Africa, " every scratch or 

 puncture becomes an ulcer ; and that months are often required 

 to dry it up." 



