DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 349 



It appears from these experiments that the minimum-lethal dose of this extract 

 is for frogs about 0*00006 grain (re.Woth) for each one hundred grains of weight of 

 frog; and for rabbits about 0*0057 grain (175th) for each pound of weight of 

 rabbit. 



A detailed account of several of the experiments contained in the tables is given 

 below, including experiments illustrative of the general effects of non-lethal as well 

 as of lethal doses. 



Experiment XI. — 0*00025 grain of extract free from fat, dissolved in 4 minims of 

 distilled water, was injected under the skin of a frog, weighing 440 grains, whose 

 respirations before the administration were 21 per 10 sec. In 14 min., the frog was 

 restless ; now and again the fore-feet were brought up to the mouth ; and the respira- 

 tions were 19 per 10 sec. No further symptoms were observed during the following 

 hour and a half. In 1 hour 56 min., the thoracic extremities were often unduly 

 extended. In 2 hours 9 min., the throat and chest respirations were 19 per 10 sec, 

 and the thoracic extremities were still unduly extended. In 3 hours 40 min., the 

 condition remained as last noted, the respiratory rate being still 19 per 10 sec. 

 On the following day, the frog appeared to be perfectly normal, with 22 respirations 

 per 10 sec. 



Experiment XII. — A frog, weighing 505 grains, received by subcutaneous injec- 

 tion 0*000312 grain of extract. Before the injection, the respirations were 24 per 10 

 sec. During the following 2 hours and 30 min., no symptom was observed 

 except restlessness; and the respirations ranged between 18 and 24 per 10 sec. In 

 2 hours 40 min., the thoracic extremities were frequently extended for several 

 minutes, and the respirations were regular in time and amplitude, and at the 

 rate of 20 per 10 sec. In 3 hours 24 min., the respirations were shallow, irregular, 

 and less frequent, and the throat was retracted. In 3 hours 50 min., the 

 respirations were very infrequent, usually only 4 occurring per 10 sec, and the 

 frog was in a normal posture, and jumped well on slight irritation. In 4 hours 

 4 min., the mouth was occasionally opened widely, the frog moved about restlessly, 

 and though usually in a normal attitude, now and again the thorax subsided on 

 to the table. On the following day, 26 hours after the administration, the frog- 

 was lying on the abdomen and thorax, with the muzzle resting on the table ; the 

 four limbs were loosely and irregularly extended ; and, when the frog was placed 

 on the back, no cardiac impact could be seen. On the third day, 50 hours after 

 the administration, the skin was pale, and there was some stiffness of the thoracic 

 extremities. On the fourth day, general rigor was present. 



Experiment XIII. — A frog, weighing 485 grains, received by subcutaneous injec- 

 tion 0000375 grain of extract. It was kept under continuous observation for three 

 hours, but no abnormal symptoms were seen, and the respirations were maintained 

 at the original rate of between 19 and 22 per 10 sec. On the following day, 

 20 hours after the administration, the frog was pale in colour, motionless, and 



