On the Infliience of the Brain, &c. 405 



handle, and go thnuigh the usual process of restoring (he 

 niercurv in the globe lo the niagaxine. This omission (it 

 is to be ff marked) occassions no error, only ihc next day's 

 observation becomes a reckonina, for two davs. 



LXXir. Further Experiments and Observations- en the 

 Ivfivence of the Brain on tl),e Generation of Animal Heat. 

 By B. C. Bkodie, Esq. F.R S. Commnnicated !o the 

 Society for promoting the Knowledge (f minimal Che- 

 mistry, and by them to tfie Royal Society*. 



[Contiuufci from vol. xxxvii. page 452.] 



AN the Croonian Lecture for the year 1810, I gave an ac- 

 count of some experunents, which ltd me to conclude that 

 the production of animal heat is vcrv much under the in- 

 fluenceof the nervous system. Some circumsiances which 

 I have since met with, iliuslrale tliis subject, and seem to 

 confirm the truth of my former conclusions. 



In an animal which is' under the influence of a poison 

 ihat operates by disturbmg the functions of the brain, in 

 proportion as the sensibility becomes impaired, so is the 

 power of generating heat impaired also. 



If an animal is apparently dead from a poison of this 

 descri[)tion, and the circulation of the blood is afterwards 

 maintained by means of artificial respiration, the sieneration 

 of heat is found to be as completely destroyed, as if the 

 head had been actually removed. 



Under these circumstances, if the artificial respiration is 

 kept up until the effects of the poison cease, as the animal 

 recovers his sensibility, so does he also recover the power 

 of generating heat ; but it is not till the nervous enerify is 

 completely restored, that heat is produced in sufficient 

 quantity to counteract the cold of the surrounding atmo- 

 sphere t. 



In the experiments foririerly detailed, as well as in those 

 just mentioned, I observed tliat the blood underwent the 

 usual alteration of colour in the two systems ni' ca[)illary 

 vessels, while carbonic acid was evolved Irom the lui;gs at 



* From the Pliilo'opliical Transactions for 1«1'J, part ii. 



■f- 'Jlic poison employed in this experiment slmiiki he- tlie essential oil of 

 almondu, or some oilier, the eflects of wliicli Rpee<hly subside. If the wnorara 

 is eiiiployrd, o long a time elap»es before tiie poibon te.'se-i to ixert its In- 

 fluui>e, that ii becomes necessary that tlie exi)erlment should be made in a 

 high tcnijicrature, otiierwise the great loss ol heat which takes plate, is 

 fulltcienc to prevent recovery. 



C c 3 each 



