TETANUS 65 



In a similar manner repeat the experiment upon a hyoglossus. 

 The experiment may be further modified by reducing the rate of 

 rotation of the drum to 1 cm. per second. In this way fig. 63 was 

 obtained, the magnification being twofold. The figure brings out 

 clearly the same points as those we have already studied in the pre- 

 ceding instance. With the slower rate of recording surface the way 

 in which the lines joining the apices or bases of the successive 

 contractions ascend is very clearly seen. 



Take a tracing of complete tetanus employing the Neef's hammer 

 of the coil for the purpose, when a tracing similar to curve 7, fig. 62, 

 p. 62, will be obtained. 



Experiment 3. — To effect this, attach the two poles of a battery to the two 

 pillars of the coil, and adjust the vibrating hammer until it works continu- 

 ously. Insert a Du Bois key in the secondary circuit as a short-circuiting 

 key. Excise a nerve-muscle preparation and fit it in a myograph, laying the 

 nerve across the electrodes. Upon a slowly moving surface record the result 

 of stimulation of the nerve for a short time. Repeat, varying the strength of 

 the stimuli. 



