STROPHANTHTJS SARMENTOSUS : ITS PHARMACOLOGICAL ACTION. 



351 



Table IX. — Intravenous Minimum-Lethal Dose of Extract for Rabbits. 



No. of 

 Experiment. 



Weight of 

 Animal in grams. 



Actual Dose 

 in grams. 



Dose per kilo- 

 gram of Animal 

 in grams. 



Result. 



40 

 41 

 42 

 43 

 44 



2180 

 2290 

 1830 

 1800 

 2950 



0-00218 



0-00229 



0-002 



0-00216 



0-0059 



o-ooi 

 o-ooi 



0-0011 

 0-0012 

 0-002 



Recovery. Severe effects. 

 Recovery. Severe effects. 

 Recovery. Severe effects. 

 Death in 1 hour. 

 Death in 4 minutes. 



From the foregoing Tables, it appears that, when the extract is injected into the 

 subcutaneous tissues, the minimum-lethal dose per kilogram is in frogs about 0'0035 

 gram; in rats, about 0"3 gram; in rabbits, about 0'0015 gram; and in cats, about 

 0-002 gram.* 



In rabbits, the intravenous minimum-lethal dose is about 0"0012 gram per kilogram. 



With reference to the subcutaneous administration of the extract, in general terms 

 rabbits and cats are equally susceptible, frogs are twice as resistant as, and rats 200 

 times more resistant than, rabbits. 



A detailed account of several of the experiments in the Tables is given below to 

 illustrate the symptoms produced by large non-lethal and by lethal doses, t 



B. General Effects. 



(a) Experiments on Cold-blooded Animals. — Frogs. 



Experiment VII. — Into the dorsal lymph-sac of a male frog [Rana esculenta) 

 weighing 33 grams, 0"0001089 gram of extract, dissolved in Ringer's solution, was 

 injected (equivalent to 0*0033 gram per kilogram, or ^ of minimum-lethal dose). Before 

 the injection the throat and flank respirations were regular and at the rate of 20 per 10 

 seconds; the nose reflex, conjunctival reflex and sacral reflex were acute. During 45 

 minutes succeeding the injection, no symptoms appeared. In 1 hour 35 minutes, the 

 throat respirations were 25 per 10 seconds, and irregular in amplitude; the flank 

 respirations were 16 per 10 seconds and irregular in time; the flanks were distended ; 

 the frog jumped well and would now remain on its back ; and the cardiac impacts were 

 6 per 10 seconds. In 3 hours 45 minutes, the throat and flank respirations were 23 per 

 10 seconds, regular and shallow ; the nose, conjunctival and sacral reflexes were acute ; 

 the frog's head and throat rested on the floor of the tray ; its limbs were flexed ; it 

 could jump well, but landed clumsily, and remained when placed on its back ; the flanks 



* The extract of S. sarmentosus used in these experiments is thus shown to possess only one-fifth of the lethal 

 power in frogs and one-half in rabbits of the similarly prepared extract of S. hispidus which was used in the experi- 

 ments with the latter substance made by one of us (Trans. E.S.E., vols. xxxv. and xxxvi., 1890 and 1891). 



t In this and in the other sections of the investigation, several other experiments were made, which gave results 

 concording with those in the experiments that have been recorded. 



