BIOCHEMISTRY: ABEL AND PINCOFFS 
511 
As to 'ts properties, the substance must be classed with the secondary 
albumoses. It has been shown to be precipitated by saturation of its 
solution with ammonium sulphate. It is non-coagulable on boiling, 
gives the biuret reaction (hemi-biuret) very beautifully, as also Pauly's 
reaction, while Knoop's bromine reaction for histidine is entirely nega- 
tive. This negative result with Knoop's reagent excludes the presence 
of histidine as an admixture in our substance.^ Picric acid added to an 
aqueous solution gives a precipitate. The addition of Millon's reagent 
gave rise to a slight turbidity, but on boiling the characteristic red color 
was not obtainable. In this respect there was entire agreement with a 
secondary albumose which we have isolated from the mucosa of the 
small intestine. The ninhydrin reaction was positive when made in the 
usual manner but we are confident that this is due to the fact that ad- 
herent amino acids were not entirely removed. To do this would have 
required several reprecipitations with ammonium sulphate. 
The albumose here described was found to have a quite negligible 
action when tested with the virgin cat's uterus. 
A secondary albumose which was prepared by digesting fresh thy- 
roid glands of the pig behaved in every respect like the above substance. 
Its specific rotation was found to be [a]^ = —88.1°, while that of the 
pituitary albumose varies from —78° to —89°. 
We come now to the filtrate from the complete salting out with ammonium 
sulphate. This was freed from ammonium sulphate in the usual manner. 
Reduced to a small volume, the solution was dropped into absolute alcohol, 
the precipitation being completed with ether as with the preceding substances. 
The material thus obtained was readily soluble in water and gave the usual 
response of pituitary extracts when tested on the isolated uterus of the virgin 
guinea pig. It also still gave the Pauly and the biuret reactions, though with 
greatly lessened intensity as compared with the original solution. It fails to 
give Knoop's reaction for histidine so that we must conclude that this amino 
acid does not exist as such in any considerable amounts, if at all, in pituitary 
extracts. The rotation of 0.0381 g. in 1 cc. of water in a 0.5 dcm. tube was 
found to be —0.52°, from which [a]^ = —27.4°. We have here a substance 
which may be compared with respect to physiological activity, rotation and 
chemical tests with Flihner's 'hypophysin' fractions 2 and 3. The solution 
used in the polarizing tests was saturated with powdered ammonium sulphate 
and again the characteristic precipitate of albumose was produced, though, 
naturally, it was not abundant this time. Evidently we have here the remnant 
of albumose which remained in solution after the first saturation with ammonium 
sulphate. If we were to apply this salting out to larger quantities of pituitary 
extract it is possible that more or less of a true peptone would be found in the 
filtrate. Certainly, there always remains in the filtrate, even after two 
