19 
end of an hour the heart of the animal was exposed and examined. 
If the heart was found completely paralyzed the dose was too large; 
if pulsation still continued the amount was too small. The correct 
“end reaction” adopted by the writers was “paralysis” of the apex 
of the ventricle, but at the base of the ventricle there should occa- 
sionally be a faint wave of contraction while the auricle, though 
much distended, would continue to pulsate regularly. When the 
correct dose was found the amount necessary to kill a frog of standard 
weight (40 grams) was calculated by a simple proportion. 
Famulener and Lyons found the reaction of the frogs very uniform, 
for not more than one or two out of a dozen healthy frogs showed a 
variation in susceptibility of as much as 10 per cent. To avoid this 
source of error, when they had determined the minimum dose in the 
manner indicated, they took a further series of three frogs, injecting 
into one the minimum dose, into a second a dose 10 per cent above 
the minimum, and into the third a dose 10 per cent below it. If 
any of this latter series showed irregularities further corrections 
were made. More uniform results were obtained by this method 
than could be obtained in the assay of such drugs as opium and nux 
vomica by chemical means. The authors give a table showing the 
results of their examination into the activity of the pure principles 
of digitalis and related drugs as well as of the galenical preparations. 
A very important contribution in their paper is a comparative study 
of the digitoxin content of three preparations of digitalis fluid 
extract with their activity* as determined by physiological methods. 
This was referred to earlier in our article (p. 9). 
Wolff® made a short report upon the biological dosage of digitalis 
preparations commenting upon the findings of Frankel and quoting 
Professors Robert and Gottlieb upon the necessity for a government 
station for the standardization of digitalis preparations. He then 
describes the method adopted by Brunnengraber, of Rostock, to 
bring into the market uniform preparations of these drugs. The 
leaves are collected on sunny days from wild plants before they 
begin to flower, carefully sorted to free them from any foreign leaves, 
and are then dried quickly in a vacuum at a definite temperature. 
In this way the fermentation which the leaves usually undergo during 
slow drying is avoided. Tinctures prepared from leaves, dried in 
this way, were examined by Professor Robert, who reported them 
free from harmful split products and high in content of active prin- 
ciples. Strophanthus tinctures were also prepared from the fresh 
green seeds of S. Rombe which had not been freed from fat and 
these too were very active. An infusion made from 5 milligrams of 
digitalis leaves produced systolic standstill of the frog’s heart as did 
also 0.02 c. c. of the tincture of strophanthus. 
a Wolff, Therap. d. Gegenw., Berlin u. Wien, 1902, XLIII, 423. 
