186 
POPULAR SCIEXCE PtEVIEW. 
fall in the thermometer sweeps away our population according 
to age so ruthlessly and decisively. 
If we analyze the facts fimther by the side of the diseases 
which kill^ we find those diseases to be numerous in name^ but 
all of one type ; they are diseases which of themselves tend 
either to produce undue loss of force, or that tend to prevent 
the development of force at its origin. Disorders which are 
accompanied with exhaustive loss of fiuids from the body, 
such as diabetes, dropsies, and hemorrhages are of the first 
class ; disorders in which due supply of air to the lungs is 
prevented, are of the second class, especially chronic bron- 
chitis, which is in truth the assigned cause of two-thirds at 
least of the deaths that succeed immediately on the fall of the 
thermometer. 
In what has been written above I have stated simply and in 
open terms the fact that the fall of temperature produces a spe- 
cified series of results, by reducing the force of the living 
organism, and disposing it to die. We may from this point 
investigate the mode by which the effect is produced in the 
economy in a physiological point of view. How does the decline 
of temperature act ? Is the process simple or compound ? 
The process is compound, and into it there enter three 
elements. In the first place, the body is robbed rapidly of 
its waste force, and the reserve and active elements of force 
are consequently called upon to the depression of the organism 
altogether. This obtains because the medium surrounding 
the body, the air, unless it be artificially heated, receives from 
its contact with the body a larger proportion of heat than can 
be spared ; and it might be possible to produce such an influ- 
ence on the body by sudden extraction of its heat as to 
destroy it at once by the mere act. A man, as Metcalfe has 
remarked, a man half plunged into a bath of freezing mercury 
would die instantaneously, as from shock, by the immediate 
extraction of his heat. But in ordinary cases, and under 
ordinary circumstances, the mere rapid extraction of heat 
is not sufficient to account for all the mischief produced by a 
low temperature ; for we take measures, by the use of non- 
conducting clothing, to counteract the mischief, and that, too, 
in a manner which proves pretty successful. We may, there- 
fore, leave this element of extraction of heat as most important, 
but not all effective for evil. 
The second element is the effect on the process of oxidation 
of blood. We all are aware that if a portion of dead animal or 
vegetable matter be placed at a low temperature, it keeps for 
a considerable tiijie ; and we have evidence of dead animals 
which, clothed in thick ribbed ice, have been retained free from 
putrefaction for centuries. Those ghastly bodies thpd occupy 
