EVOLUTION OP HEAT. 627 



Le Gallois 1 and Chossat 3 are decidedly confirmatory of this conclusion, whilst 

 they extend it to other lesions of the Nervous centres, the influence of which 

 upon the calorific function appears to be proportional to their severity. Various 

 pathological phenomena, moreover, indicate that the withdrawal of nervous in- 

 fluence from any part of the body usually tends to produce a depression of its 

 temperature, and this especially in the extremities; thus, Mr. H. Earle 3 found 

 the temperature of paralyzed limbs slightly lower than that of sound limbs ; so 

 Prof. Dunglison has noticed that in one case of hemiplegia of five months' stand- 

 ing, the temperature of the axilla was 96 on the sound side, and 96 on the 

 paralyzed, whilst that of the hand was 87 on the sound side and only 79 J on 

 the paralyzed; and in another case of only a fortnight's duration, the tempera- 

 ture of the axilla was 100 on the sound side, and only 98 i on the paralyzed, 

 whilst that of the hand was 94 on the sound side, and 90 on the paralyzed. 4 

 But it is a remarkable fact, that the disturbance of temperature produced by 

 severe injuries of the Nervous system occasionally shows itself in the opposite 

 direction. Thus, it has been noticed by many experimenters that one of the first 

 effects of division of the spinal cord in the back, in warm-blooded animals, is to 

 raise the temperature of the posterior part of the body, this elevation continu- 

 ing for some hours. A case is recorded by Sir B. Brodie, in which, the spinal 

 cord having been so seriously injured in the lower part of the cervical region 

 that the whole of the nerves passing off below were completely paralyzed, the 

 heat of the body, as shown by a thermometer placed on the inside of the groin, 

 was not less than 111; and this notwithstanding that the respiratory function 

 was very imperfectly performed, the number of inspirations being considerably 

 reduced, and the countenance being livid. 5 And Prof. Dunglison states that, 

 notwithstanding the usual depression of the thermometer on the hemiplegic 

 side, it is not unfrequently found to be more elevated than on the sound side. 6 

 According to the recent experiments of M. Cl. Bernard, 7 it appears that an ele- 

 vation of temperature constantly takes place on one side of the face, when the 

 trunk which unites the Sympathetic ganglia of the neck on that side is cut 

 through; this increase being not only perceptible to the touch, but showing 

 itself by a thermometer introduced into the nostrils or ears, even to the extent 

 of from 7 to 11 Fahr. When the superior cervical ganglion is removed, the 

 same effect is produced, but with yet greater intensity. This difference is main- 

 tained for many months, and is not connected with the occurrence of inflamma- 

 tion, congestion, oedema, or any other pathplogical change in the part ; more- 

 over, it is not prevented from manifesting itself by the division of any of the 

 cerebro-spinal nerves of the face. It is remarkable that the sensibility of the 

 parts thus affected should be no less augmented than their temperature. 



[Dr. Brown-Sequard has observed the same remarkable phenomena as those 

 detailed by M. Cl. Bernard, but he regards them as mere results of the 

 paralysis, and of the consequent dilatation of the bloodvessels. In conse- 

 quence of this dilatation, the blood reaches the part supplied by the nerve in 

 larger quantities; the nutrition is therefore more active. The increased sensi- 

 bility is a result of the augmented vital properties of the nerves when their 

 nutrition is increased. Dr. Brown-Sequard has likewise noticed the increase of 

 temperature of the ear over that of the rectum, to the amount of one or two 

 degrees Fahr.; but it must be remembered that the temperature of the rectum 

 is a little lower than that of the blood, and as the ear is gorged with that fluid, it 



1 " Annales de Chimie," 1817; and "(Euvres de M. Le Gallois," torn. ii. 



2 "Memoire sur 1'Influence de Systeme Nerveux sur la Chaleur Animale." 



3 " Medico-Chirurgical Transactions," vol. vii. 



* "Human Physiology," 7th edit., vol. ii. p. 238. 



6 "Medical Gazette," June, 1836; and "Physiological Researches," p. 121. 



6 "Amer. Med. Intelligencer," Oct. 18, 1838. 1 "Gazette Medicale," Fevr. 21, 1852. 



