DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 381 



In this experiment, therefore, the muscles of the frog (A) that had received Stroph- 

 antus soon became stiff, and fibrillary twitches occurred in them, and, finally, they 

 became non-contractile and hard within I hour and 15 min. after the ventricle of the 

 heart had ceased to contract ; whereas, in the control experiment (B), the muscles remained 

 contractile for 24 hours after the heart had been ligatured, and no fibrillary twitch or 

 stiffness of the muscles was observed during the experiment. The experiment accord- 

 ingly demonstrates that the stoppage of the circulation produced by the action of 

 Strophanthus on the heart is not the cause of the paralysis of the skeletal muscles, or 

 of any of the other phenomena observed in them after the administration of Strophanthus. 



In the next experiment it is shown that the muscle paralysis is not caused by any 

 influence conveyed by the motor nerves or originating in these nerves. 



Experiment LVIII* — One-twentieth of a grain of sulphate of methyl -stryehnium, 

 dissolved in 4 minims of water, was injected under the skin at the left flank of a 

 frog, weighing 296 grains. One hour thereafter, galvanic stimulation of the exposed 

 left sciatic nerve failed to produce any muscular contraction in the left pelvic extremity 

 or elsewhere. A ligature was then passed below the left sciatic nerve, and tied 

 tightly round the middle of the left thigh ; the nerve, therefore, not being included in 

 the ligature. Five min. afterwards, O'l grain of extract of Strophanthus was injected 

 under the skin at the right flank. On the following day, 23 hours after the adminis- 

 tration of Strophanthus, both thoracic extremities and the right pelvic extremity were 

 distinctly rigid ; and exposed muscles in these extremities and in the trunk did not con- 

 tract under galvanic stimulation. The left (ligatured) pelvic extremity, however, was 

 flaccid and freely mobile, and its muscles were contractile. On the second day, the 

 conditions were the same as on the previous day ; the muscles in the regions to which 

 Strophanthus had direct access being non-contractile and stiff, while those in the 

 left (ligatured) pelvic extremity continued to be contractile and flaccid. On the 

 third day, the muscles in the left pelvic extremity, as well as elsewhere, failed to 

 contract under galvanic stimulation. 



The next experiments render it obvious that the changes produced in the muscles 

 are due to a direct action of Strophanthus upon them. 



Experiment LIX. — The blood-vessels of the right thigh were ligatured, and the 

 heart exposed, of a frog, weighing 320 grains. After a short interval, the cardiac 

 contractions were found to be regular and at the rate of 14 per 30 sec. 0"1 grain 

 of extract of Strophanthus was then injected under the skin at the left flank. In 

 9 min. after the administration of Strophanthus, the heart's ventricle had ceased to 

 contract and had become pale and small, but the auricles continued contracting 

 at a gradually diminishing rate for 28 min. longer. In 37 min. after the 

 administration, the frog was able to jump only feebly, and the mouth was at times 

 widely opened. In 1 hour 42 min., the frog was on the abdomen and thorax, with 

 the thoracic extremities adducted and extended stiffly at right angles to the body ; 



* Published in 1872 in Journal of Anatomy and Physiology, vol. vii. p. 152. 



