Islo MUSCLE. 



Arrange the drum contact in the P circuit. Guide mark 

 on paper, S key closed after ascertaining that the muscle 

 responds. Load 10 g . 



As the muscle (gastrocnemius) is capable of giving several 

 hundred contractions, the gradual transformation of the muscle 

 curve would be obscured by the number inscribed on the 

 paper ; therefore only record every 25th or 30th contraction. 



Adjust the recorder point to write with an equable pressure, 

 so that there is just,. enough play in the point to meet the 

 inequalities of the paper when the pillar handle is against 

 the stop. Start the drum. 



After the usual few preliminary turns of the drum, open 

 the S key and apply the writing point as the guide mark passes, 

 and lift it off again just before the end of the revolution. 



Count from this onwards 29 contractions, and inscribe the 

 30th, and continue so doing until the muscle is exhausted. 



The curves will gradually lengthen, the chief change being 

 the slowing of the relaxation of the muscle. The height will 

 fall until final extinction of the contractions occur. 



To obtain a second curve use the other limb of the frog. 



11 Influence of the load on the work done by muscle. 

 This may be carried out under the following circumstances : 

 1. As a load acting continuously and increased 



(a) By the successive addition of separate weights, 



(b) By rapid increase in the weight, by causing the 



muscle to pull against a strong spring (isometric 

 method). 



Required: Inductorium, 2 Leclanche cells, 2 keys, 7 wires, and 

 2 fine, ten 10 weights, muscle chamber with fine wires substituted for 

 the platinum electrodes. Nerveless muscle preparation. The drum and 

 P key are operated by hand. 



