49 
THE BLOOD PRESSURE METHOD OF ASSAY. 
The blood-pressure method, included in a third group by our 
classification, was carried out in the ordinary manner, cats being 
used as experimental animals. They were anaesthetized with chlore- 
tone, 0.4 gram per kilogram body weight, dissolved in a small amount 
of alcohol (2 c. c. to 1 gram chloretone) diluted with a little water 
and given by the stomach after the method of Edmunds and Cushny. a 
The comparison of the various preparations of digitalis is made upon 
the percentage of rise in blood pressure which followed the injection 
of 1 c. c. of the various solutions when diluted with normal salt solu- 
tion to tincture strength. Only one preparation could be used upon 
one animal, and from two to four animals were used for each prepa- 
ration in order that the average of the results obtained might more 
accurately represent the value of the drug used. The results of 
these experiments, which are tabulated in Table III, page 37, are sum- 
marized in the following table: 
Table VIII . — Summary of results obtained on blood pressure. — Average per cent rise 
after 1 cubic centimeter doses intravenously . 
N. B. and Co 
Mulford No. 2. . . 
Digitalone No. 2. 
B. W. and Co... 
P., D. and Co . . 
S. and D. 
PI. B. and W... 
Merrell 
Digitalone No. 3. 
Lloyd Bros 
Digitalone No. 1. 
Preparation. 
Per cent 
increase. 
99 
55 
51 
37 
35 
33 
26 
26 
24 
1-23 
i Fall. 
To enable a comparison to be made of the relative strengths of 
the different digitalis preparations as obtained by the different 
methods of assay employed, we have grouped all the findings in 
Table IX. 
Table IX.— Summary of results obtained by the several methods for the standardization 
of digitalis preparations. 
LETHAL-DOSE METHODS. 
Mice. 
Guinea pigs. 
Frogs (twelve-hour). 
Cats. 
mg. 
Mulford No. 1 4 
B. W. and Co 4 
Merrell 6 
H. B. and W 7 
P., D. and Co 8 
N. B. and Co 9 
S. and D 9 
Digitalone No. 1 22 
Lloyd Bros 24 
mg. 
B. W. and Co.. . 0.35 
H. B. and W 5 
Merrell 6 
Mulford No. 1. . . .7 
P., D. and Co... .7 
N. B. and Co ... .9 
S. and D 9 
Lloyd Bros 9 
Digitalone No. 1 . 5. 0 
Digitalone No. 3. & 1. 5 
B. W. and Co.. 0?015 
Mulford No. 2 .. .020 
S. and D 027 
P., D. and Co.. .029 
mg. 
B. W. and Co 158 
P., D. and Co 171 
N. B. and Co 192 
Mulford No. 2 195 
H. B. and W 219 
S. and D 242 
Merrell 252 
Digitalone No. 3.. 280 
Llovd Bros 438 
Digitalone No. 2. . 550 
a Edmunds and Cushny, Laboratory Guide in Experimental Pharmacology, p. 12. b Lived. 
65051— Bull. 48—09 1 
