22 
acid shows an optical activity of — 51.40'^ and that of 
the pure natural 1-adrenalin obtained from the bitartrate showed 
an optical activity of = — 51.40°. The d-adrenalin dis- 
solved in weak hydrochloric acid showed an optical activity of 
= +51.80 and, like its optical isomer, melts at 211° to 
212° C. (uncorrected), and it forms oxalates and chlorides which do 
not crystallize. 
The physiological activity of these new products was tested by 
Abderhalden (1) (1908) and Muller, and reported in a very unsatis- 
factory manner. The 1-adrenalin was found to be fifteen times more 
active than the d-isomer. 
Cushny (18) (1908) in a very brief report states that he tested the 
synthetic d- and 1- adrenalin prepared by Flacher, finding the syn- 
thetic 1-adrenalin equal in potency to the 1-adrenalin obtained from 
glands. It was found difficult to determine the absolute relative 
ph}^siological activity of the synthetic d- and the synthetic 1- adrenalins, 
but in general ten times more synthetic d-adrenalin was required 
than of the synthetic 1- to produce a given rise of blood pressure. 
It was calculated that the relative physiological activity of the d- 
and 1- products were in the ratio of 12:1. In the light of these 
experiments the relative activity of the natural 1-adrenalin and the 
synthetic dl-adrenalin may be expressed by the ratio 24:13. 
Although Emmert’s work (30) (1908) has to deal primarily with 
histological changes ensuing from repeated injections of sublethal 
doses of adrenalin, some interesting toxicological data is recorded. 
The number of mice used by him does not seem to have been 
large, and hence the dose given as lethal must not be taken too 
seriously. It is stated that 0.1 mg. generally caused death in from 
one minute to sixty honrs. In one case he was able to increase 
gradually the dose to as much as 0.5 mg. before acute poisoning set 
in. In another case three mice were injected with 0.1 mg. once or 
twice a day for 9, 24, and 39 days. In still another experiment mice 
were observed for 109 days, fifty-six 0.033 mg. doses being first 
injected, and later twenty-five 0.1 mg. doses. Only three mice lived 
after doses of 0.1 to 0.15 mg., and these were always prostrated by 
each of the twenty-five injections given in the course of 24 days. 
For the object of studying lesions caused by repeated injections his 
experiments are perhaps sufficient, but for purposes of determining 
the lethal dose they are not. 
