90 Curative Influence of the 



been more fully appreciated than by the great Hippocrates, who, 

 in his labours on e})idemic disorders, has left us, amongst other 

 treasures, his admirable and persevering example in accurately 

 tracing its effects ; and indeed, the influence of atmospheric vicissi- 

 tudes on the constitution, is one of the most important subjects of 

 enquiry connected with the duties of the physician, from the great 

 power which they exercise on the functions of animal Hfe. 



" The primary influence of the air which surrounds us, on the 

 body, may be considered as resulting from a twofold operation : its 

 action on the lungs, and that on the surface of the skin, and it is 

 through the medium of each of these operations that its beneficial, 

 or injurious properties, are imparted to the constitution. 



" The effects of the atmosphere also exhibit themselves in a strik- 

 ing manner in the change of season, not only in the removal, but 

 also in the production of diseases; and the same is not less ob- 

 servable, as I have already noticed, under the prevalence of certain 

 winds ; all which circumstances are highly interesting and impor- 

 tant in a curative point of view." 



In noticing the effects of a cold and dry atmosphere, the 

 author remarks, 



" The diseases to which this cold and dry state of the atmosphere 

 chiefly predisposes, are inflammatory affections ; and it is more 

 especially productive of rheumatism, coughs, catarrhal fevers, and 

 inflammatory disorders of the lungs and chest ; all which are, there- 

 fore, more frequently met with in high elevations than in the valleys. 

 Jn such diseases, therefore, this kind of atmosphere becomes per- 

 nicious, not only by the cold constricting the substance, and super- 

 ficial vessels of the body, but by the irritation produced by its im- 

 mediate contact with the vessels of the lungs ; and, by the same 

 operation, from its power of quickening the circulation through 

 them ; since the respective velocities of any fluid are inversely as the 

 capacities of the canals through which it is propelled. 



" There is, however, another cause, which usually renders such a 

 state of the atmosphere injurious to persons much debilitated by 

 disease ; for as their afflictions incapacitate them from taking a 

 sufficient degree of bodily exercise, the constricting force of the ex- 

 ternal cold, becomes superior to the enfeebled power of the circula- 

 tion ; and that of the exhalents on the surface, and the active func- 

 tions of the latter, which are so conducive to health, become checked 

 by the torpor thus induced, whence the whole frame necessarily 

 sympathizes in the derangement. 



" An atmosphere, however, which is very cold, and moist, is far 

 more generally prejudicial to invalids than the former ; for such a 

 state of the air, so far from imparting appreciable advantages, is 

 constantly succeeded by a great variety of disease. I have already 

 observed, that the prejudicial influence of a cold and dry atmosphere 

 on a debilitated system, although arising, in some degree, from the 

 absolute abstraction of heat by contact, is chiefly communicated 



