14 
the heart ancl death of the animal. He considered the frog as the 
most suitable animal upon which to test the relative activity of the 
members of this group as mammals vary considerably in their sus- 
ceptibility to them. In his earlier experiments he did not weigh the 
animals, but later adopted this precaution, regarding the weight as 
being a factor of some importance, but at the same time not consider- 
ing that the action of the drug upon different frogs is in any absolute 
relation to their weights. The frogs he employed were an average 
size, being between 25 and 30 grams. He confirmed some of the 
results obtained on frogs by experiments upon guinea pigs, the com- 
parative results being as follows : 
Animal used. 
Toxic dose. 
Fluid ex- 
tract con- 
vallaria. 
Fluid extract 
digitalis. 
No. 26. 
No. 6. 
R. temporaria, average size 
Guinea pig, per 100 grams 
c.c. 
0.003 
.006 
c. c. 
0.02 
.01 
c. c. 
0.04 
.02 
It will be seen that the two digitalis preparations show exactly the 
same ratio on both animals. 
In 1895 Prevost ® repeated his experiments upon these preparations 
to see if they had deteriorated in the intervening time. In this case 
he used R. esculenta, realizing, however, that they did not offer the 
same susceptibility as R. temporaria. 
Mile. M. Piotrowska b studied the comparative toxicity of a num- 
ber of the members of this group and the effect upon their toxicity of 
the mode of administration, whether subcutaneously or by the mouth. 
For this purpose she used frogs (R. temporaria) almost exclusively, 
determining the toxic dose and comparing them on a basis of 100 grams 
body weight. Some of her results she confirmed by determining the 
toxic dose for cats and rabbits, comparing them on the basis of kilo- 
grams of body weight. 
The examination of the plant dialysates was made the subject of 
investigations by several workers, one of the earliest being Jacquet. 0 
These dialysates were prepared by Golaz of Yevey, Switzerland, from 
fresh plants and made of such strength that 1 part of dialysate corre- 
sponded to 1 part of leaves. By using great care in the collection of 
the leaves, gathering them in the same region during sunny weather, 
using them fresh, and making the product up to a uniform volume, 
it was believed that a definite dosage of digitalis was attained, as 
« Prevost, Rev. med. de la Suisse Rom., Geneve., 1895, XV, 453. 
t> M. Piotrowska, Inaug. Dissert., Geneva, 1896. 
c A. Jacquet, Cor.-Bl, f. schweizer Aerzte, 1897, XXVII, 326. 
