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. Larrey 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 reentering 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 



