508 
BIOCHEMISTRY: ABEL AND PINCOFFS 
behalf of the chemists of the research laboratory of the Farbwerke- 
Hoechst Company. 
From extracts of the posterior lobe of the hypophysis, which had been 
freed of coagulable proteids,^ these investigators obtained a mixture of 
crystalline sulphates of high physiological activity which was quite 
unjustifiably named ' Hypophysin. ' What misconceptions may arise 
in connection with the use of this term 'hypophysin' — a designation for 
an unknown number of substances — may be seen when we read in a 
treatise on organotherapy that ''Hypophysin is the chemically active 
pure posterior pituitary hormone, marketed as a sulphate."^ 
Further research enabled the chemists referred to to separate their 
'hypophysin' into four unnamed crystalline fractions which, in respect 
to physical and chemical properties, are easily distinguished, the one from 
the other. These fractions are described in the following words: 
1. A colorless, well crystallized sulphate which easily dissolves in water 
with neutral reaction and is difficultly soluble in alcohol, acetone and ethyl 
acetate. It is optically active (laevo-rotatory, [aJu = —54.02°) and carbon- 
izes without melting when heated to a high temperature. The Pauly and 
biuret reactions are positive. With picric acid this substance forms a salt 
difficultly soluble in water. 
2. There was also obtained a substance yielding a well crystallized, colorless 
sulphate which dissolves in water with faint acid reaction and is likewise 
difficultly soluble in alcohol, acetone, ethyl acetate, etc. The optical rotatory 
power of this preparation is [a]j^ = —27.17°; it decornposes when heated to 
198-200°C. and gives the Pauly and biuret reactions. Contrary to the sub- 
stance described under (1) this compound forms a picrate easily soluble in 
water. If this substance is brought into contact with alkalies a volatile 
amine base is at once liberated. 
3. A third substance was isolated in the form of a crystalline, faintly yellow 
sulphate which, to be sure, is present in only very small amount. It is easily 
soluble in water and methyl alcohol with faintly acid reaction, and difficultly 
soluble in absolute alcohol, acetone and ethyl acetate. It turns the plane 
of polarized light to the left; its rotatory power is {a\^ = — •39.25°. On 
heating the substance decomposes at 185-186°C. The Pauly and biuret 
reactions are positive. With picric acid is obtained a salt easily soluble in 
water. 
4. The mother liquor remaining after the fractional precipitation of the 
three substances just described yields, on cautious evaporation in a vacuum, 
a brittle, glassy, hygroscopic mass which dissolves easily in water and methyl 
alcohol, with difficulty in ethyl acetate and acetone. The solution of this 
substance shows an optical rotatory power of = —21.26° and gives the 
Pauly but not the biuret reaction. Recently it has been found possible to 
