152 NATURE AND LIFE. 
ganizing its globules, and it is this alteration which, either 
at once or when the blood beomes fluid again, destroys all 
the vital functions. lLarrey relates the case of Sureau, 
chief apothecary of the French army in Russia, who, when 
chilled to freezing by a painful march in the snow, did not 
_ die until the moment they began to restore warmth. Ex- 
periments on animals show that they keep themselves alive 
as long as they are maintained in a state of half congelation, 
and die whenever their temperature and circulation are so 
far restored as to permit the blood-globules, disorganized 
by cold, to be diffused throughout the vessels. Death oc- 
curs, therefore, whenever the quantity of these globules is 
sufficient to produce a considerable disturbance in the sys- 
tem, that is, whenever the frozen part is at all extensive. 
An animal entirely frozen, and consequently containing in 
its congealed blood no globules but those unfit for life, is 
dead, without possibility of resurrection. Thawing it only 
restores a soft, flaccid, discolored body, with opaque eyes, 
If freezing only attacks a limb, it becomes gangrenous, and 
is destroyed. Pouchet deduced from these examinations a 
judicious, practical conclusion. If it is true that, in cases 
of partial freezing, the death of the individual is due to 
the disorganized globules reéntering the circulation and 
corrupting the blood, it is plain that, the more sudden 
the invasion of these globules is, the more rapidly death 
will supervene. It follows, that, by resisting this inva- 
sion, by means of ligatures, or extremely slow thawing, 
_ we might succeed in preventing the poisoning. The dis- 
eased globules which, pouring in a flood into the heart 
and lungs, would imperil life by the sudden alteration 
of the blood, will apparently disturb it merely in an un- 
important way, if they are dropped into the blood by slow 
degrees. 
Thus the late researches of experimental physiology ex- 
plain for us the effects of heat and cold, regarded as toxic 

