ZOOLOGY. 330 



of the " divinrag~rod," and vibration of bodies suspended from the 

 finder ; both which have been clearly proved to depend on the state 

 of expectant attention on the part of the performer, his will being 

 temporally withdrawn from control over his muscles by the state of 

 abstraction to which his mind is given up, and the anticipation of a 

 given result being the stimulus which directly and involuntarily 

 prompts the muscular movements that produce it. 



INFLUENCE OF THE NERVOUS ACTION UPON HEAT. 



THE following is an abstract of a paper read before the French 

 Academy, by M. Bernard, taken from the Comptes Rendus, xxxiv. 



" When w r e cut in the region of the neck of a mammiferous animal, a 

 dog, a cat, a horse, or a hare, for example, the nervous thread of com- 

 munication which connects the cervical superior, and the cervical in- 

 ferior ganglion, we will find, immediately, an increase of temperature 

 on the corresponding side of the face of the animal. This elevation of 

 temperature makes its appearance instantaneously, and is developed so 

 quickly, that in a few moments, and under certain circumstances, we 

 shall find a difference of temperature between the two sides of the face 

 of 3 or 4 Centigrade, (5 or 7 Fahr.) This difference of heat 

 is perfectly appreciable by the hand, though determined more con- 

 veniently by introducing, for the purpose of comparison, a small ther- 

 mometer into the nostrils or auditory conduits of the animal. 



This difference of 3 or 4 of temperature, is remarkable as a rela- 

 tive difference of heat between the two sides of the face. If, however, 

 we compare the heat of the nostril or auditory conduit, (although 

 warmed by the section of the nerve,) with the heat of the rectum, or 

 central parts of the body, the thorax or the abdomen, we see that it is 

 almost the same. Thus the section of the cervical fillet of the 

 sympathetic nerve of the hare, elevates the temperature of the corres- 

 ponding ear as high as 4U, while the normal temperature of the rec- 

 tum of the same animal, does not vary much from 38 or 39 

 Centigrade. 



The whole of the side of the face warmed by the section of the 

 nerve, becomes the seat of a very active circulation of the blood, the 

 arteries become much more full, and appear to pulsate stronger, as 

 may be distinctly observed in the vessels of the ear of the hare. But 

 in a few days, sometimes the next day, this vascular turgescense is 

 considerably diminished, or disappears entirely, although the heat of 

 the cut side of the face, continues as at first. This circumstance leads 

 us to infer that the elevation of temperature, is not altogether an 

 effect of the increased activity in the circulation of the blood. Still, 

 after observing, for a long time, the animals which present this 

 phenomena, (and I have observed during twelve or fourteen days in 

 the hare, and for many more in the dog,) I have never seen it happen, 

 after the experiment, that the parts became more warm without con- 

 gestion, and those morbid phenomena we are accustomed to associate 

 with what we call inflammation." 



