The Action of TJrginea Burkei (Baher). 
199 
noteworthy that in many cases at the end of the hour there was little 
evidence of loss of power in the frog's muscles, but the cardiac action was 
well developed. 
The frogs used were the South African variety, Rana ]ilatana. They 
were treated with strophanthin that had been used in England on Bana 
temjjoraria. The English and South African frogs required the same dose 
per gramme of strophanthin to produce systolic arrest of the heart. 
(c) General Action on Mammals. 
In thirty-eight experiments the tincture or extract of Urg'tnea Burhei, 
dissolved in Ringer's solution, was injected subcutaneously into rats, rabbits 
and cats. 
A few minutes after injection of a lethal dose the respirations were 
greatly accelerated, and there was, as a rule, profuse salivation. The animal 
soon began to sway from side to side and to drag its hind legs when walking. 
The muscular weakness progressed, and soon afterwards the animal lay 
down on its side apparently quite powerless. The respiration was slow, 
and, in many cases, irregular and gasping. Coma developed, in a few 
instances preceded by convulsions, and a few minutes afterwards the heart 
and respiration ceased. No vomiting occurred, but three animals made 
retching movements. 
Sublethal doses produced symptoms of less severity. A dose less than 
one-third of the minimal lethal dose was followed by depression or salivation, 
or had no apparent effect. 
The frec^uent occurrence of vomiting when the drug was given by mouth, 
and its absence when intravenous or subcutaneous injections were made, 
would point to the chief cause of vomiting being reflex from irritation of the 
stomach. 
(d) Minimal Lethal Dose for Eat and Bahhit. 
The minimal lethal dose of the extract for the rabbit by subcutaneous 
injection is 0'025 grm. per kilogramme of body-weight, and for the rat 
0'4 grm. The rat therefore has a certain degree of natural tolerance for 
the poison as compared with the rabbit, the minimal lethal dose being 
sixteen times as great. 
D. Action on the Circulatory System. 
(a) Action on the Isolated Frocfs Heart. 
The contractions of the isolated frog's heart were recorded by perfusion 
through a cannula tied into the inferior vena cava. A second cannula was 
inserted into the left branch of the aorta and all the other vessels were 
tied. Einger's solution was perfused until the heart became regular, then a 
solution of the tincture or extract was perfused. 
