THE CHANGE IN FORM 



343 



The Muscle Warmer. l A disk, supported by a 

 rod, bears three pins (Fig. 59). One of the three pins 

 is prolonged and bent at a right angle near its lower 

 end. To the bend is fas- 

 tened one end of the mus- 

 cle under experimentation. 

 About the other end is tied 

 a fine copper wire \vhich 

 passes through a hole in 

 the disk to reach a muscle 

 lever. A second opening in 

 the disk is provided with a 

 short metal tube, in which 

 a thermometer is held by 

 a piece of rubber. The 

 bulb of the thermometer 

 may be placed on a level 

 with the belly of the 

 muscle. When these ad- 

 justments are complete, a 



fflaSS cylinder is brought FlG - 59 ~ The muscle warmer; 



an apparatus for studying the in- 



against the under surface fluence of temperature on mus- 

 . , . , , , cular contraction. 



of the disk, where it is held 



in position by the "spring" of the three pins. A 

 beaker or other vessel containing water is now 

 placed beneath the cylinder and raised until the 

 cyclinder is sufficiently immersed. The temperature 

 of the muscle is altered by heating or cooling this 



1 American Journal of Physiology, 1904, x, p. xliii. 



