A STUDY IN MORBID AND NORMAL P U Y S I L G Y. 7 



Experiment 14. 



A very large, powerful tomcat was used, and bladder fitted to head at 10:30 A. m. 



Time. Temp, of Wateb. EEJIARK.S. 



10:35 a.m. 1750 p. 



11 140 Very hurried breathing. 

 11:30 180 



12 M. 160 Cat is now uncmiscious: the unconsciousness came on in a very short space of time, 



but not with absolute abruptness ; uo convulsions ; respiration slower. 

 12:15 P.M. 175 Cat just dead. The respiration certainly ceased before the heart some seconds, or 



probably a minute or two. No convulsion. 



Autopsy. — Brain opened instantly after death. The thermometer phina:ed directly into the .sub- 

 stance rose above 11-1' F. ; when placed, however, so as to be in contact with the inside of the skull, 

 it marked 115°. There was decided, but not extraordinary, congestion of the brain. 



As these experiments are painful ones, I liave not repeated them furtlier. They 

 seem sufficient to establish the following conclusions : Fir.st. A temperature of the 

 brain of from 113° to 117° F. is sufficient, if maintained, to produce death in a 

 short space of time in mammals by arrest of the respiration. Second. That the 

 chief symptoms induced are insensibility and convulsions, preceded by exceedingly 

 rapid respirations and action of the heart, and unaccompanied by any general rise 

 of temperature. Thinl. That these symptoms come on very quickly in all cases, 

 at times with absolute abruptness. 



The resemblance of these symptoms, induced by the local application of heat to 

 the head, to the nervous phenomena of sunstroke, is very striking, both in regard 

 to the symptoms themselves and also to the suddenness of their onset. A reference 

 to the account of the exposure of cats to a general high heat, will sliow that 

 in these animals the nervous symptoms are much more sudden and severe than 

 in rabbits; in fact, approaching what is seen in man. The experiments just 

 detailed demonstrate that a temperature of 113° to 114° F. is f;ital to the brain 

 of the cat, whilst, at least m some cases, that of 117° F. is required to destroy the 

 vitality of a rabbit. The nervous system of the cat is much more excitable, and 

 much more impressible, than that of the rabbit, and consequently feels the abnormal 

 temperature more acutely. The brain of a man is much more highly organized, 

 and no doubt correspondingly more sensitive, than that of a cat ; and if a tempera- 

 ture below 113° F. be fatal to the brain of a cat, whose normal temperature is 102°. 5 

 F., it seems very certain that the temperature of some cases of insolation (113° F.) 

 is sufficient in itself to cause death in man, Avhose normal temperature is 99° F. 



In connection with the above experiments, I have performed others to determine 

 whether, when heat is applied to the head, coma is developed at the same tempera- 

 ture as it is when the whole body is heated. In these the hot-water bonnet was 

 applied to the head of the animal. 



