the heart stopped in systole in two minutes, while with the second 
sample it continued to beat for hours. The difference in physiological 
activity was also shown by means of graphic records. 
The results obtained on the frogs were confirmed by the injection of 
5 milligrams of each sample into two guinea pigs, the length of time 
till death occurred serving as a means of comparison. 
Similar methods of comparison were also employed by Laborde® 
in his study of the purity and activity of the digitalines in use at the 
hospitals of Paris. 
Gley 6 compared the toxicity of ouabaine and strophanthin by 
means of experiments upon several varieties of animals. Upon frogs 
he showed that with equal doses of the two drugs ouabaine would 
stop the heart in half the time that strophanthin would. He then 
compared the toxic dose of the two drugs upon guinea pigs, dogs, and 
rabbits; in the latter case injecting the drugs into the vein of the ear, 
in the other cases using subcutaneous injection. 
Reusing c carried out a series of experiments comparing the actions 
of strophanthin and digitalis upon the frog’s heart, employing two 
methods in his work. In the first he studied the effect directly upon 
the exposed heart, the pericardium not being opened. In the second 
method the Ludwig-Coat’s heart apparatus was employed, the per- 
fusion fluid to which the drugs were added consisting of two parts of 
0.65 per cent NaCl solution with 1 part of defibrinated hog blood. 
Bardet d undertook in the same year an examination of the relative 
activity of the various active principles of digitalis and employed the 
simplest method which is in use to-day to standardize these drugs, 
viz, that of determining the lethal dose for animals, using frogs and 
rabbits. 
An examination of a number of the so-called digitalines of com- 
merce was made by Fouquet/ who ascertained the toxic dose of the 
different samples when they were injected hypodermically into frogs, 
rabbits, and dogs. In this way he studied the relative activity of 
crystallized and amorphous digitalin, digi toxin, and digit alein. 
In 1893 Prevost i examined a number of the preparations which 
had been included in the Swiss Pharmacopoeia III, among them being 
some members of the digitalis group. His experiments w T ere carried 
out upon frogs (mainly R. temporaria), upon which he sought the 
minimal dose of the drug which would produce definite stoppage of 
^Laborde, Comp. rend. hebd. d. Sean, et Mem. de la Soc. de Biol., 1884, XXXVI, 
599. 
b Gley, Comp. rend, des Seances de l’Acad. de Sci., 1888, CVII, 348. 
c Reusing, Uber die Einwirkung des Strophanthin auf das Froschherz, Inaug. Dissert, 
Wurzburg, 1889. 
d Bardet, Bull, et Mem. Soc. de therap., Par., 1889, 2d ser., XVI, 253. 
e Fouquet, Bull. gen. de therap., 1892, CXXII, 71. 
/ Prevost, Rev. Med. de la Suisse Rom., Geneve., 1893, XIII, 505. 
