ARTIFICIAL RHYTHM. 177 



This artificial rhythm may be obtained with a 

 portion of in-itable tissue of any size, and whether 

 a large or small piece of the tissue employed be 

 included between the electrodes. 



As the fact of this wonderfully rhythmic response 

 to faradaic irritation was quite unexpected by me, 

 and as it seemed to be a fact of great significance, 

 I was led to investigate it in as many of its bearings 

 as time permitted. First, I tried the etfect on the 

 rhythm of progressively intensifying the strength 

 of the faradaic current. I found that with each 

 increment of the current the rate of the rhythm 

 was increased, and this up to the point at which 

 the rhythm began to pass into tetanus due to sum- 

 mation of the successive contractions. But between 

 the slowest rhythm obtainable by minimal stimula- 

 tion and the most rapid rhythm obtainable before 

 the appearance of tetanus, there were numerous 

 degrees of rate to be observed. I here append 

 another tracing, to show the effect on the rate of 

 the rhythm of alterations in the strength of the 

 current (Fig. 20). 



It will also be observed from this tracing that, in 

 consequence of the current having been strengthened 

 slightly beyond the limit within which strictly 

 rhythmic response was attainable, the curves in the 

 middle part of the tracing, where the current was 

 strengthened, are slightly irregular. This irregu- 

 larity is, of course, due to the first appearance of 

 tumultuous tetanus. If the faradaic stimulation 

 had in this case been progressively made still 

 stronger, the irre;rularity would have become still 



