384 DR THOMAS It. FRASER OH STROPHANTHUS HISPIDUS. 



a solution of extract of Stropkanthus or of strophanthin, dissolved in saline, and again 

 record the movements and stimulated contractions of the muscle. 



When a muscle, with the above arrangements, was placed in a solution of Stroph- 

 antus, the first change observed was a shrinking or shortening of the muscle, which 

 was manifested by elevation of the point of the lever. In some of the experiments, this 

 shortening occurred so rapidly as very soon to require a readjustment of the lever. It 

 usually reached its maximum early in the experiment, and retained this maximum until 

 the end ; but in a few experiments, relaxation gradually took place before the termination 

 of the experiment. 



At some considerable time after a solution of Strophanthus has been in contact with a 

 muscle, slight jerking movements of the lever, produced by spontaneous fibrillary twitches, 

 are observed. These movements gradually become more frequent and larger, until incessant 

 movements occur of small and large size, and of great irregularity in time and character. 

 They, bye and bye, again become smaller and less frequent, and, finally, they altogether 

 cease. Curves produced by these spontaneous fibrillary twitches of the muscle are repre- 

 sented in Plate VIII., tracings 4 and 5 ; Plate IX., tracings 4 to 10 ; and Plate XL, tracings 

 2, 3, and 4. It has already been stated (p. 376) that the time of their cessation nearly 

 coincides with the time when the motor nerve is no longer able to excite contraction of the 

 muscle ; and this coincidence will further be illustrated in Experiments LXII. and LXVI. 



When the spontaneous fibrillary twitches have ceased, or nearly ceased, if the muscle 

 be directly stimulated, a remarkable change is observed in the character of its contraction. 

 It may, in general terms, be described as a delay in the attainment of the state of 

 relaxation. This delay is produced in two ways chiefly. In one, after the attainment of 

 the first complete, or nearly complete, relaxation, quickly succeeding the stimulated 

 contraction, the muscle again contracts, and the subsequent contraction and relaxation 

 are of mueh longer duration than the original ones. These abnormalities are illustrated 

 in Plate VIII., tracings 3, 7, and 8, and Plate IX., tracings 13, 14, 15, and 16. 



The other chief way in which the delay of relaxation is produced, is by a great prolonga- 

 tion of the period both of maximum contraction and of subsequent relaxation. When 

 curves illustrating this description of abnormality are examined (Plate X., tracings 3 to 

 8; Plate XL, tracings 7 to 10 ; and Plate XII., tracings 3, 4, and 5), it is seen that 

 after an initial maximum has been briskly attained, the curve either continues slowly to 

 rise further before it begins to fall, or it at once begins slowly to fall ; but, in both cases, 

 the fall is so gradual that many revolutions of the recording cylinder are made before the 

 base-line is reached. In both varieties, this fall, usually, is at first slow, then rapid for a 

 brief period of time, until the abscissa is nearly reached, and, finally, again slow to the 

 abscissa. 



From a considerable number of experiments, during each of which many tracings were 

 taken, the following six experiments, with a few of their tracings, are given for the 

 purpose of illustrating the foregoing statements. 



Experiment LXI. — The gastrocnemius muscle placed in 0"6 per cent, saline, and 



