CAUSATION: PREDISPOSING INFLUENCES.
(Concluded from page 53.)
Cold has long been recognized as one of the most energetic of the predisposing causes of pneumonic fever, although the proposition has been denied by some. I have myself no doubt regarding the predisposing influence of exposure to cold and wet in the causation of the disease, and it is to this I attribute the preponderance of persons attacked whose habits and occupations lead to such exposure.
It was the impression of Laennec that cold, as a cause of pneumonic fever, was much less active when it temporarily followed excessive heat.
Thus "the Russian who rolls himself in the snow after coming out of the hot bath, or the baker who goes from his heated oven, almost naked, into an atmosphere below zero, is not liable to attacks of this disease."
I may add that I have seen iron and lead