150 NATURE AND LIFE. 



the blood, which is the condition of the heating, then occurs 

 with much greater activity. Let us add that quite lately 

 Demarquay applied this toxic action of heat on the muscles 

 in the happiest manner, and without suspecting it. He 

 cured patients suffering from those frightful muscular con- 

 tractions which characterize tetanus, by subjecting them to 

 the influence of caloric, and making them take very hot air- 

 baths. The rise of temperature in the tetanized muscles 

 was sufficient to modify them, and restore them to a healthy 

 state. Here the poison worked a cure. 



Such are the effects on animals of the elevation of tem- 

 perature. Let us now see what becomes of them when im- 

 mersed in cold media. Some curious facts with respect to 

 the freezing of certain animals have long been known. 

 During his voyage to Iceland, in 1828 or 1829, Gaimard, 

 having exposed in the open air a box filled with earth in 

 which toads were put, opening it after a certain time, found 

 the reptiles frozen, hard and brittle ; but they could be re- 

 stored to life when put in warm water. Many ancient au- 

 thors cite similar cases, and we can almost bring ourselves 

 to understand how a great English physiologist might for 

 a moment have given them the whimsical interpretation 

 that he did. John Hunter fancied it might be possible to 

 prolong life indefinitely by placing a man in a very cold 

 climate, and there subjecting him to periodical freezing. 

 The man, he said, would perhaps live a thousand years, if, 

 at the end of every ten years, he were frozen for a hundred, 

 then thawed out at the end of the term for ten years more, 

 and so continuously. " Like all inventors," Hunter adds, " I 

 expected to make my fortune by this scheme, but an exper- 

 iment completely undeceived me." Putting carp into a 

 freezing mixture, he observed, in fact, that, after being en- 

 tirely frozen, they were dead, past recovery. The case is 

 the same with all other animals, as the late and very re- 

 markable experiments of F. A. Pouchet have proved. 



