and the Action of Cold upon Animals. 221 



vation and experiment to the examination of hibernation ; but 

 it was especially towards the commencement of the present cen- 

 tury, that important researches were made into this phenome- 

 non, in consequence of the recommendation of the Academy of 

 Sciences. M. Flourens cited in Germany the works of MM. 

 Herold and Raffin ; in Italy, that of M. Mangili ; in France, 

 those of MM. Saissy, Prunelle, &c. M. Flourens' own experi- 

 ments form a supplement to those of these able observers. 



They were made in France, and on the Lerot, a small animal 

 of the dormouse family. The author began with briefly describ- 

 ing the entire state of the torpid animal, aiv^j^the conditions of 

 its resuscitation, two circumstances respecting which the ob- 

 servers who preceded him left little to be desired. During the 

 lethargy, the animal has an orbicular and regularly bent posi- 

 tion, the muzzle applied against the belly, the hind-feet carried 

 forwards, the fore-feet placed against the breast, the ears lying 

 upon the sides of the head, the eyes firmly closed, the whole 

 body drawn together in a lump, and the tail rolled all round 

 the body. A slight excitement does not waken the animal, but 

 a powerful one does. The phenomenon of hibernation presents 

 two distinct degrees of lethargy. In the one, the imperfect 

 lethargy, the respiration is suspended, and renewed by turns, 

 every three, four or five minutes, for example. In the other, 

 the perfect ktltargy, respiration entirely ceases. M. Flourens 

 has often seen this cessation last for whole hours. 



After the example of Spallanzani, he submitted sevei-al torpid 

 animals to the action of various mephitic gases, and the results 

 at which he arrived agree with those of his illustrious predeces- 

 sor, inasmuch as they place beyond doubt the total suspension 

 of respiration in the perfect lethargy. In this kind of lethargy 

 the circulation is suspended as well as the respiration. At first 

 there is no beating in the arteries of the limbs. If a vein or an 

 artery is opened, either no blood at all issues, or it comes slowly, 

 of a dark colour, and in drops. If the heart be touched, it is 

 only found to offer some obscure and rare motions. 



The temperature of hibernating animals, which, like that of 

 others, is in their ordinary state at 38 centigrade degrees (100° 

 Fahr.), descends in the lethargic state to 5, 4, and even 3 de- 

 grees. 



Jl^r.Y OCTOBER 1829. Q 



