A STUDY IN MORBID AND NORMAL PHYSIOLOGY. 145 



siblc that the action of tlic cortical centres upon tliermogcnesis is merely tliat of a 

 local vaso-motor influence ; the action must involve the whole muscular system, 

 and it would seem probable that it should be able to make itself perceived by an 

 eff'ect upon the blood pressure. To determine whether the vaso-motor system 

 of the muscles is capable of modifying arterial pressure at all, the following ex- 

 periments were performed. In them a curarized dog, with splanchnics and pneu- 

 mogastrics cut, had his sciatic nerve irritated by a faradic current. Section of the 

 splanchnics is believed to cause complete vaso-motor palsy of the abdominal 

 vessels, and the question was whether after such palsy the contraction of the re- 

 maining arterioles of tlie body produced by irritating a sensitive nerve would be 

 able to make an impression upon the arterial pressure. 



Experiment 98, 



A docf. Cnrari g:iven ; artificial respiration; pneumogastrics cut; left splanclinic (as shown by 

 autopsy) completely severed above the diaphragm; right splanchnic divided except a corner of the 

 sheath with possibly some nerve (ibres reiuainiug in it ; sciatic nerve exposed. 



Time. Arterial PiiEssrRE. Irritation. KEIMAKKS. 

 Sec. (Millimetres.) 



30 



1 30 Current applied, 

 4 37 



G 44 



12 52 



1.5 53 



18 52 Current brolieu. 



22 40 Fig. 4, Plate I Y, represents the tracing of this E.xperiment; I repre- 



sents the point at which the circuit was closed ; 0, that at which 

 it was broken. 



30 37 



36 29 



Experiment 99. 



A dog. Curari given; artificial respiration; par vagum divided; sciatic nerve exposed. Wound 

 of the brain: right side, the iirst convolution, outer part of the sulcus cruciatus; left side, wound 

 entirely in advance of the left sulcus cruciatus. 



Time. Arterial Pre.ssure. Irritation. KEIMARKS. 

 Sec. (Millimetres.) 



45-35 Current applied. 



2 82-62 Disturbance of respiration very marked, but no struggles. 



4 78-58 



14 68-55 Current broken, 



21 45-37 



More curari given and splanchnics cut, as shown by the autopsy, just below the last rib. 



19 July, 1880. 



