APPENDIX I. 113 



theoretically.* Professor Fick attached the plate 

 to a heavy pendulum, and although the velocity then 

 was no longer uniform, yet the law of its variation 

 was known. j" 



The speaker himself had formerly devoted much 

 attention to the improvement of the rotating 

 myographion, and had suggested some alterations of 

 it, which, executed by that most skilful instrument- 

 maker, M. Sauerwald, of Berlin, answer remarkably 

 well, and have done good service in some very 

 important researches, hereafter to be mentioned, if 

 For the present occasion, however, he contrived a 

 new myographion which in simplicity far exceeds 

 every previous design, and which may be styled the 

 spring-myograpJiion. As in Harless's and in Pro- 

 fessor Fick's myographion, in the spring-myo- 

 graphion the cylinder is replaced by a glass plate 

 moving in its own plane. But instead of being 

 impelled by gravity, the plate, on pulling a trigger, 

 is, as it were, shot by a spiral spring along two 

 horizontal steel wires which act as supports and 

 guides. The curve is traced on the plate, after this 

 has reached its greatest velocity, i.e., after the spring 

 has passed through its position of equilibrium. On 

 account of the friction, however, the velocity of the 

 plate cannot be taken as uniform, nor can the law of 

 its variation and its amount at any given place 



* Abhandlungen der K. Bayer. Aliademie der Wiss. II. CL, 

 Bd. ix., Abtb. ii. Miinchen, 1862. S. 361. 



t Vierteljahrschrift der Naturforschenden Gesellschaft in 

 Zurich, 1862, S. 307. 



$ A. v. Bezold, Untersuchungen uber die elektrische Errejung 

 der Nerven und Musheln. Leipzig, 1861. S. 85. 



I 



