DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 389 



regularity at the rate of 12 per 30 sec. ; respiratory movements still continued, and the 

 frog was able to jump about actively. In 18 min., the auricles were motionless and 

 dilated, having previously become irregular in their contractions. In 36 min., respiratory 

 movements still occurred, though at irregular intervals, but they soon afterwards 

 ceased. 



Experiment LXIX. — In this experiment, 0*025 grain of extract was injected under 

 the skin of a frog, weighing 226 grains ( = 0'011 grain per 100 grains of animal), whose 

 heart had previously been exposed, and found to be contracting at the rate of 16 per 30 

 sec. In 5 min. after the injection, the contractions were slightly irregular, and at the 

 rate of 17 per 30 sec. In 6 min., the contractions were arhythmical. In 7 min., the 

 ventricular systole was greatly prolonged, and diastole was imperfect. In 8 min., the 

 ventricle contracted 9 times per 30 sec, but its diastole now consisted merely of 

 dilatation of small portions of the ventricle. In 9 min., the ventricle had altogether 

 ceased to contract, and had become pale and small. The auricular movements ceased 

 in other 4 min., and then irritation of the ventricle or of the auricles was not 

 followed by movement of any part of the heart. In 34 min., the frog could jump with 

 considerable activity, and respiratory movements still occurred. In 38 min., the frog 

 could jump only imperfectly, but even at this time an occasional respiratory movement 

 was observed. 



Strophanthin, also in doses considerably above the minimum-lethal, was administered 

 in the next two experiments. 



Experiment LXX. — The exposed heart of a pithed frog, weighing 385 grains, was 

 found to be contracting with regularity at the rate of 21 per 30 sec. 0'005 grain of 

 strophanthin in 5 minims of water was injected under the skin of the left flank. In 4 min., 

 the heart's rate was 18 per 30 sec. In 10 min., it was 12 per 30 sec, and the ventri- 

 cular systole was markedly prolonged, and the diastole imperfect. In 13 min., only a 

 small part of the base of the ventricle dilated during diastole. In 14 min., diastolic 

 dilatation could scarcely be observed in any part of the ventricle, and two auricular 

 contractions occurred for each imperfect ventricular contraction. Almost immediately 

 afterwards, the ventricle altogether ceased to contract, and it remained permanently 

 small, pale, and inexcitable ; and in other 2 min. the auricular movements also ceased. 

 In 43 min., the heart has removed, and a section of the muscle of the ventricle was 

 found to be acid in reaction. 



Experiment LXXI. — A frog, weighing 350 grains, received by subcutaneous injection 

 0"00125 grain of strophanthin dissolved in 5 minims of water ( = 0'00035 grain per 100 

 grains). In 7 min., the thoracic extremities were frequently in an unduly extended 

 position, respiratory movements were active, and the frog jumped about naturally. In 

 22 min., no obvious change having occurred in the above conditions, the frog was pithed, 

 and the heart exposed. The heart was found to be perfectly motionless, with the 

 ventricle very pale and small, and the auricles, especially the left, large and dark. In 

 26 min., mechanical irritation of the heart failed to produce any movement. 



