SYMPATHETIC NERVE. 



471 



while a partly fluid, partly solid exudation 

 surrounded the heart, forming in some parts 

 adhesions between it and the pericardium. 



From the experiments of Krimer it appears 

 that division of the renal nerves gives rise 

 to changes in the constitution of the urine. 

 According to his observations this fluid, after 

 the nerves have been divided, contains al- 

 bumen as well as the red colouring matter 

 of the blood, these increasing in the same 

 proportion as the normal ingredients diminish 

 in quantity. Similar results were also ob- 

 tained by Brachet* in dividing these nerves. 

 He cut the renal artery and with it the nerves 

 leading to the kidney, and then connected the 

 two extremities of the cut vessel by means 

 of a canula so as to keep up the flow of blood. 

 The fluid which passed off by the urethra 

 contained fibrin and albumen as well as the 

 red colouring matter or haematine. Analogous 

 experiments were also performed by Mliller 

 and Peipers.f A ligature was applied around 

 the renal vessels of the dog and sheep so 

 tightly as to destroy the nerves, and again 

 relaxed in order to allow the circulation to 

 be re-established. Only in one case did they 

 observe the secretion of urine continue in the 

 kidney, the nerves of which had been de- 

 stroyed, and in this case it contained blood as 

 also hippuric acid. The kidney itself was 

 more or less injected, and rapidly became 

 disorganised. 



As regards the influence of the sympathetic 

 on the circulation, it has been already stated, 

 that division of the sympathetic in the neck 

 is followed very rapidly by distension of the 

 vessels of the conjunctiva. From experiments 

 lately made by Bernard, it also appears that 

 in the rabbit the vessels of the ear on the 

 same side in like manner become immediately 

 distended with blood, so that the ear appears 

 quite red, while at the same time its tempe- 

 rature, as well as that of the whole side of 

 the lace, rises so considerably, that the dif- 

 ference between it and that of the opposite 

 side is distinctly appreciable to the touch. 

 This experiment I have repeated several 

 times. In a rabbit to which ether had been 

 given, the temperature of the two ears rose 

 to about 95 F., the vessels at the same time 

 being much distended. The sympathetic was 

 then divided about the middle of the neck : 

 shortly thereafter the temperature of the ear 

 on the side on which the nerve was not 

 divided, sunk to 85, and its vessels became 

 much less distended. The temperature of 

 the ear on the side on which the nerve had 

 been divided, still continued as high as 95, 

 its vessels also remained distended, and were 

 felt pulsating forcibly. On examining the two 

 ears an hour or so afterwards the tempera- 

 ture of that upon the side on which the nerve 

 had been divided, was still felt to be dis- 

 tinctly warmer than the other : its vessels 

 were also still distended, and pulsating for- 

 cibly. How long the effects produced upon 



* Op. cit. p. 326. 



j 1 De Nervorum in Secretioues Actione, p. 26. 



the temperature and blood-vessels continue I 

 have not been able to ascertain : they are 

 certainly not so permanent as the contraction 

 of the pupil. While this remains contracted 

 for weeks, or even months, no difference in 

 the condition of the two ears can be distin- 

 guished a week or so after the nerve has been 

 divided.* 



* The elevation of temperature, according to 

 Bernard, begins immediately after the nerve is 

 divided, and is so quickly developed that in a few 

 minutes, in certain circumstances, the difference in 

 temperature of the two sides of the head may rise 

 to 4 or 5 centigrade. This difference of tempera- 

 ture is perfectly appreciable to the hand, but is 

 better determined \>y introducing a small ther- 

 mometer into the nostril or ear of the animal. Re- 

 moval of the superior cervical ganglion is followed 

 by the same effects as section of the sympathetic 

 cord, only these effects are always more rapid, more 

 intense, and more durable. After section of the 

 sympathetic cord in rabbits the phenomena of ex- 

 cess of sensibility and calorification are scarcely 

 observable beyond five to eighteen days, while in 

 dogs they may continue for six weeks or two 

 months. After ablation of the ganglia in these 

 animals the persistance of the phenomena may be 

 regarded as indefinite: in a dog in which the 

 superior cervical ganglion of the left side had been 

 removed all the phenomena of excess of sensibility 

 and calorification due to that operation were very 

 intense a year and a half after the extirpation of 

 the ganglion, when the animal was sacrificed for 

 other purposes. The temperature of the side of the 

 head on which the operation has been performed is 

 nearly the same as that of the central parts of the 

 body, such as the abdomen, thorax, or rectum ; 

 sometimes, however, it is higher, being 40, while 

 the temperature of the internal parts is 38 to 39. 



The increase of temperature is also attended by 

 an increase in the activity of the circulation, 

 as is very distinctly seen in the ear of the rabbit. 

 But in the following days, or even on the day after 

 the operation, the vascular turgescence diminishes 

 considerably, or disappears, while the heat of the 

 face continues to be very well developed. It is 

 found, by passing the bulb of a small thermometer 

 into incisions properly made, that the elevation of 

 temperature observed on the superficial parts of the 

 head extends to the deeper parts as well, and even 

 into the cavity of the cranium and substance of the 

 brain. This is better observed after extirpation of 

 the superior cervical ganglion. The blood itself, 

 which returns from parts so heated, also possesses 

 a higher temperature. The side of the head on 

 which the temperature has been so raised, presents 

 also a greater resistance to the effects of heat and 

 cold, when the animal is placed in a stove where 

 the ambient heat is greater than that of the body; 

 while the sound side becomes warmer, the other 

 does not. When placed in a colder medium than 

 its own body, the whole side loses temperature 

 more rapidly than the other. There is also a sort 

 of exaltation of vitality on the side on which the 

 operation has been performed, the involuntary 

 movements continuing longer on this side than in 

 other parts of the body. 



When the cephalic extremity of the cut sympa- 

 thetic nerve in a dog is galvanised, not only does 

 the pupil become larger, but all the other phe- 

 nomena which followed division of the nerve disap- 

 pear, and the opposite take place ; the pupil becomes 

 larger than that of the opposite side ; the eyeball pro- 

 jects; the vascularisation disappears; and the tem- 

 perature sinks below normal. When the galvanisa- 

 tion is stopped, then the phenomena caused by 

 section of the nerve reappear. 



By Walter and Brown Sequard the elevation of 

 temperature is attributed to an increased afHux of 



H H 4 



