512 
BIOCHEMISTRY: ABEL AND PINCOFFS 
saturations, a substance which gives a pink biuret reaction. Only more ex- 
tended research can show to what extent this is albumose and to what extent 
peptone. 
We believe that there is no mystery attaching to the constituents of 
pituitary extracts that have been shown to give positive Pauly and 
biuret reactions and a negative Knoop's bromine reaction. These con- 
stituents must be classed as albumoses (and even peptones) and the 
German chemists are to be congratulated if they have obtained them in 
the form of physiologically active crystalline sulphates, as has been stated 
on their behalf by Fiihner, even though they have failed to recognize 
their proteid nature. 
We have made qualitative tests with other commercial pituitary 
extracts (Armour's Pituitary Liquid, and Solution Pituitary Extract, 
Mulford) and have found, as was to be expected, that albumoses can be 
salted out from all of them. The amount of proteid material present 
varies considerably in these preparations — one of them (Armour's 
Pituitary Liquid) appears to have only a trace of that form of proteid 
(coagulable proteid plus primary albumoses) which gives a precipitate 
with potassium ferrocyanide and acetic acid and to have practically all 
its biuret-yielding substance in the form of secondary albumose. 
As to the total amount of biuret-yielding material present in the extract 
analyzed — and by this we mean the substance or substances that give 
the biuret reaction immediately at room temperature (and not, as histidine 
gives it, after heating) — we beheve that we are close to the truth when we 
say that it cannot be far below 10% in weight of the total solid matter. 
The dry residue from five bottles of extract (73 cc), exclusive of chlor- 
etone, was found to be 0.415 g. The amount of albumose, primary (?) 
and secondary, recovered from ten bottles (in the analysis described 
above), with a dry residue of 0.830 g., was approximately 0.050 g. 
The losses, at a conservative estimate, could hardly have been less than 
0.025 to 0.030 g. On this basis we should have had, in the specimen 
analyzed, close to 10% of biuret-yielding material. 
It may be of interest to state here that when the dry residue of five 
bottles (0.415 g.) was heated in a boiling water bath for one hour in 10 cc. 
of 25% hydrochloric acid the biuret reaction^ disappeared entirely but the 
Pauly reaction for histidine was still obtained. The disappearance of 
the biuret reaction after boiHng with hydrochloric acid can only be 
interpreted as due to hydrolysis of our albumose. 
After having completed our examination of the American pituitary prep- 
arations we learned that the 'hypophysin' of the Hoechst chemists could be ob- 
