17 
pulses, the presence of which is held to prevent imnlriasis. The 
enucleated frog’s bulbus placed in a small vessel of 5 c. c. capacity 
with a knovTi amount of adrenalin was compared with controls in 
physiological saline. He mentions that there is considerable indi- 
vidual variation, but in the subsequent paragraphs and the reviews 
of his article this factor is lost sight of. The pupil dilated to a 
maximum in a solution of 0.001 mg. and 0.0001 mg. per c. c. pro- 
duced distinct dilation. Having, as he thinks, proved the delicacy 
of the test object, he then determines the adrenalin content not 
only of the blood after an intravenous injection of adrenalin, but 
even determines that the adrenals secrete into the blood a percep- 
tible amount of adrenalin. He overlooks, however, the fact that in 
the blood there are other substances that cause the pupil to dilate, 
not to mention certain factors discussed later which enter in to 
justify the severest criticism of his technique and conclusions. 
Meyer (57) (1906), by suspending strips of beef’s subclavian and 
carotid arteries in adrenalin solutions, concludes that with ; 
1 gm. of adrenalin to one thousand million c. c. of oxygenated Ringer, contraction 
may occur. 
1 gm. of adrenalin to one hundred million c. c. of oxygenated Ringer, contraction 
usually but not always occurs. 
1 gm. of adrenalin to fifty thousand c. c. of oxygenated Ringer, maximal contrac- 
tion usually occurs. 
1 gm. of adrenalin to one hundred c. c. of oxygenated Ringer, maximal contraction 
may occur. 
He maintains that the method is a quantitative one, and along 
with other interesting statements says that strips exposed to rather 
concentrated solutions of adrenalin (1:10,000) for eight minutes, 
removed, vdped dry, and then hung in 20 c. c. of fresh Ringer solu- 
tion for five minutes diffuses sufficient adrenalin into the new solu- 
tion to stimulate fresh strips quantitatively equivalent to a one to 
twenty million solution. 
By this time sufficient chemical data had accumulated to war- 
rant attempts to synthesize adrenalin. Stolz (68) and Dakin (21) 
succeeded, independently, in making substances closely allied to this 
product, among which proved to be dl-adrenalin. The discovery 
of these interesting compounds resulted in a new series of pharma- 
cological experiments. 
The physiological testing of synthetic substances by Dakin (21) 
and by Loewi (51) and Meyer are hardly quantitative in nature, and 
their results, though roughly comparable with each other, give only 
a general idea of the activity of the compounds. Biberfeld and 
German writers in general seem, as pointed out, to have been mis- 
led by some of the statements of Loewi and Meyer, based upon quali- 
177— Bull. 55—09 2 
