Date Endosperm for Self -Digestion. 73 
Another extract was made from fresh dry powder. After two hours 
digestion the brownish red extract gave a precipitate at the neutral point. 
Continuing the extraction over night (sixteen hours), the extract did not 
give a precipitate at the neutral point, and boiling at the neutral point was 
without apparent effect. When slightly but distinctly acid the precipitate 
settled. 
Extraction with sodium hydroxide , 2 per cent . The residue remaining 
after the extraction with sodium hydroxide, -i per cent., was exhausted sixty 
hours with a 2 per cent, solution of the same reagent. The powder imme- 
diately turned a dark blood red with a brownish tinge. The filtered 
extract was of course alkaline. On close neutralization with acetic acid no 
change occurred, not even after boiling. Continuing the acidification 
slowly, no change was apparent when a decided acid reaction was attained, 
but continuing still farther the brownish tinge gradually disappeared, 
and when strongly acid a change to cherry red occurred, and a copious 
flocculent precipitate settled. This result made it clear that a fairly large 
amount of proteid can be extracted with a proper strength of alkali. The 
•X per cent, alkali is evidently too weak to extract all the proteid. Since 
the 2 per cent, alkali, however, might have effected some decomposition of 
the proteid, it seemed best to try a moderate strength. 
Extraction zvith sodium hydroxide , -5 per cent. On adding 500 cc. of 
•5 per cent. NaOH solution to 500 grins, of freshly prepared powder the 
usual change to brownish red occurred. After forty- eight hours it was 
noticed that this colour had disappeared, and the reaction was found to be 
acid to litmus 1 . The same volume of alkali solution was then added and 
the brownish red colour returned and remained for sixty hours. On acidi- 
fication with acetic acid the filtered extract yielded a copious flocculent 
precipitate. The latter, after fusing with caustic potash, gave an unusually 
abundant yellow precipitate of ammonic-phospho-molybdate. This result, 
in connexion with the data already recorded, may be accepted as evidence 
of the presence of considerable nucleoproteid. The wet precipitate re- 
sembles the extract in colour, being perhaps more brown than red. No 
colour was imparted to any of the following reagents on stirring the still 
wet precipitate into them : aceton, methyl alcohol, ethyl alcohol, benzol, 
petroleum ether, turpentine and carbon bisulphide. Some of the matter which 
colours the precipitate is soluble in hot water, and this solution gave a 
weak reaction for tannin with ferric chloride 2 . 
Why this extract became acid after forty-eight hours while the . i per cent, extract was still alkaline 
after sixty hours is not known. The two cases are not comparable, however, because one was with 
fresh powder and the other with material which had been successively exhausted with water and 
sodium chloride. 
3 The remainder of the precipitate was studied further by Dr. Gies, as far as the quantity would 
permit, and the following observations were made by him. After drying at room temperature and 
being reduced to a powder, which was dark red, the precipitate was redissolved in dilute alkali 
