21 
is optically inactive, consists of equal quantities of the Isevorotatory 
and dextrorotatory modification, so that this substance consisted 
of three-quarters dextro and one-quarter Isevorotatory suprarenin. 
If the supposition were correct that the dextro-rotatory suprarenin 
is inactive, then this mixture could only possess one-fourth the 
activity of the natural suprarenin. Careful experiments upon 
animals with the kymograph demonstrate, however, the complete 
equivalence of this preparation with the natural substance.’’ These 
writers are not content with this statement, but even make it appear 
as if a commercial product in which they are deeply interested is, 
according to ^ ‘ a great number of clinicians and pharmacologists, not 
only equal to that obtained from the adrenal organs but its activity 
is even greater than the latter, which must be attributed to the 
absolute purity of the synthetic preparation.” 
Cushny (16) (1908), in a preliminary report, states that he exam- 
ined the products just mentioned, finding that the strength of the 
three substances — natural base, synthetic base, and the three-fourths 
dextrorotatory base — bear the relation 4:2:1. He also finds Biber- 
feld’s results divergent from his own, and offers as a possible explana- 
tion the use of rabbits which, Cushn}^ thinks, acquire a tolerance 
for adrenalin. 
Cushny (17) (1908) compared a sample of natural adrenalin the 
optical activity of which was found to be —42.25° with a synthetic 
sample optically inactive. Instead of trying, as did Biberfeld, the 
relative activity by comparing the minimal doses necessary to cause 
a rise of blood pressure he checked 1 c. c. of 1:100,000, 1:50,000, 
and 1:25,000 of adrenalin base with corresponding solutions of the 
synthetic product. Then by decreasing the dose of the stronger 
preparation and increasing that of the weaker until the rises of 
blood pressure approximated each other he was able to determine 
the relative physiological activity of each. As a result of his experi- 
ments upon dogs anesthetized with paraldehyde with both vagi cut 
and under conditions of artificial respiration he concludes that the 
‘^natural Isevoadrenalin acts twice as strongly on the blood pressure 
as synthetic or racemic adrenalin, and presumably also upon the 
other organs affected by adrenalin. From this it is inferred that 
dextroadrenalin is devoid of action on these tissues, and this is con- 
firmed by the examination of a partially isolated d-adrenalin.” 
Flacher (31) (1908) succeeded in splitting dl-adrenalin into its 
d- and 1- components. He concluded that the physico-chemical 
properties of the synthetic 1-adrenalin and the natural 1-adrenalin 
are identical. Both melt at 211° to 212° C. (uncorrected). They 
form oxalates and chlorides that do not crystallize. The synthetic 
product purified from the bitartrate and dissolved in hydrochloric 
