510 
BIOCHEMISTRY: ABEL AND PINCOFFS 
that all those fractions of 'hypophysin' which give the biuret reaction 
contain albumose. The extract called 'Pituitrin' (Parke, Davis & Co.) 
was used first because it could be purchased in large quantities (J oz. 
bottles). 
The contents of 10 bottles, approxirnately 150 cc, were extracted three 
times with ether to remove a preservative (chl ore tone) and then concentrated 
under an electric fan on the water bath to a volume of 10 to 15 cc. A small 
amount of flocculent material which separated was removed by filtration, the 
filtrate was diluted with an equal volume of absolute alcohol and a solution of 
lead acetate was added, which induced a very slight precipitation. Addition 
of ammonia to faint alkalinity did not materially increase the precipitate, 
from which it was concluded that no appreciable amount of native proteid 
could be present, and that no advantage would accrue from the use of basic 
lead acetate, as in the procedure which will be described in a subsequent paper. 
An albumose, especially if of secondary nature, would escape precipitation by 
ammoniacal lead acetate. The alcoholic filtrate was freed from lead with 
sulphuric acid and the filtrate from the lead sulphate was concentrated to a 
small volume (a few cc.) and treated with an equal volume of saturated am- 
monium sulphate solution. The resulting flocculent precipitate, which was not 
very abundant, was washed with half-saturated ammonium sulphate solution, 
dried in vacuo, dissolved in water and again precipitated with an equal volume 
of saturated ammonium sulphate solution. The precipitate was again washed 
with half -saturated ammonium sulphate solution and treated with an excess 
of barium hydroxide. After filtering off the barium sulphate, the filtrate 
was heated on the water bath until all the ammonia had been expelled and the 
excess of barium was removed with sulphuric acid. The filtered solution was 
then concentrated to a very small volume and dropped into absolute alcohol, 
ether being added until no further precipitation was produced. The substance 
here thrown out, which was small in bulk (0.010 g.), was of less interest to us 
than the fraction presently to be described. It gave the Mil Ion and biuret 
reactions, as well as that of Pauly. Knoop's reaction for histidine was 
negative. 
The filtrate from the half-saturation with ammonium sulphate as described 
above was saturated with finely powdered ammonium sulphate, which caused 
the appearance of a gummy precipitate so characteristic of albumoses when 
treated in this manner. The precipitate was filtered off, washed with satu- 
rated ammonium sulphate solution, dissolved in water and treated with barium 
hydroxide in the usual manner. The solution, freed from ammonia and the 
excess of barium, was concentrated to a very small volume and dropped into 
absolute alcohol, the precipitation being completed with ether. The substance 
thus thrown out was collected as completely as possible and dried in vacuo; 
0.031 g. in 1 cc. of water in a 0.5 dcm. tube showed a rotation of —1.38°, 
whence [ajp = —89°. When the substance was reprecipitated with hot 
absolute alcohol its specific rotation was found to be [a\jy = —77.6°. 
