21 
The author studied pure principles and also galenical prepara- 
tions, and the most important fact which he brought out and espe- 
cially emphasized in his work was the great variability in the reac- 
tion of frogs. The time of the first appearance of the action varied 
between two and six minutes, but a still greater variability was shown 
in the time of the appearance uf systolic standstill. He said he 
was greatly discouraged by the great capriciousness in the reaction 
of the frogs, and the hope of an exact estimation by physiological 
methods received a mighty blow. 
While in the estimation of his dosage he did not usually take 
into consideration the weight of the animal, yet in discussing his 
results he had several opportunities to compare the action of the 
drug upon animals of the same size. In some of his tables this fac- 
tor seems to be important, while in others it would appear that it 
could be ignored; the hearts of frogs of the same size given the 
same dose stopping in widely different times, while those of differ- 
ent sizes stopped after like intervals when given the same sized 
dose. His conclusion upon this phase of the question was that it 
was best to take into consideration the weights of the frogs in mak- 
ing an assay. Upon the important question as to the effect of the 
season upon the susceptibility of frogs he found that summer (July) 
frogs possessed far greater resistance than winter frogs. 
He points out that his results do not confirm those of the earlier 
workers, but he thinks the individuality of the animal is an impor- 
tant factor. According to this author, unless animals of about the 
same weight and of the same species can be obtained from a certain 
section of the country at the same time of year greater reliance can 
be placed upon chemical analysis. At any rate, he concluded that it 
was only in a very general way that we could tell from physiological 
experiments as to whether a preparation was good or bad, and while 
the method was not necessarily useless it was defective. 
In the same year Brondgrest® also conducted a series of experi- 
ments to compare the action of the dialysate of digitalis grandi- 
flora with digit alinum purum and the infusion of digitalis purpura. 
He employed for this purpose the frog’s heart in situ, using the sus- 
pension method combined with the Williams perfusion apparatus. 
He concluded that the dialysate of digitalis grandiflora acts the 
same as D. purpurse and as digit alinum. 
Among the numerous writers upon the subject of standardization 
no one has contributed more than Focke, ft who published several 
articles between 1902 and 1906. His method has undergone one or 
°Brondgrest, Zentrbl. f. innere Mid., Leipz., 1903, No. 24, 906. 
£>Focke, Therap. d. Gegenw., Berlin u. Wien, 1902, XLY, 44; Arch. f. Pharm., 
1903, CCXLI, 128, 669; Deutsche Aerzte Ztg., Berlin, 1904, VI, 272, 292; Therap. d. 
Gegenw., Berlin u. Wien, 1904, XLY, 250; Berlin klin. Wchnschr., 1906, XLIII, 642. 
