PENDULUM MYOGRAPH 



53 



The absolute force of a muscle varies considerably in different 

 muscles and in different animals. For mammalian muscles it is much 

 higher than in the case of the frog's muscle. Determinations made 

 upon the gastrocnemius have given results of as much as 8,000 to 

 10,000 grams per sq. cm. 



THE PENDULUM MYOGRAPH 



A form of recording surface which has been largely employed for 

 recording a single twitch of a muscle is the pendulum myograph, a 

 simple form of which is shown in fig. 55. 



Fig. 55.— Simple Form of Pendulum Myograph. 



It consists of a sheet of plate glass which is covered with glazed paper, 

 and its surface is then smoked. This glass is held in a aupport at the end of 



