METHOD OF ENUMERATING MOVEMENTS. 355 



with k, and a wire connects i with a in Fig. 51, 

 while 6 is connected with the other pole of the 

 battery. Each flexion of the finger thus allows 

 the escapement of the clock to pass one tooth, and 

 the hands indicate on the dial the number of finger- 

 flexions, and the number of times the portion of the 

 nerve-mechanism connected with the finger-flexion 

 has been in activity. 



If it be desired to record by figures the number 

 of times that certain special movements (coin- 

 cidences of movement) have been made, we may 

 proceed as follows : Let us consider only flexor 

 movements of the fingers. There are five digits; 

 it is required to count how many times each of the 

 possible combinations of flexion of the five digits 

 occurs. There are thirty-two such possible com- 

 binations of flexion. Let the digits be called A, 

 B, 0, D, E; there are thirty-two possible combi- 

 nations of these five factors, viz. ABODE, AB, 

 ABC, ABODE, etc. Now, by the following method, 

 it is possible to show, on thirty-two counters, how 

 many times each of these possible combinations 

 of finger-flexion has occurred in a given length 

 of time. 



Say it is desired to make a counter enumerate 

 how many times the digits A and B have flexed 

 together. The conducting tubes from the fingers 

 A, B are to be connected each with a contact-tam- 

 bour; then, by making the electrical connection 

 between these as indicated in Fig. 50, and includ- 

 ing the counter in the circuit, that counter will be 

 actuated every time that the fingers A, B bend 



