CLE A VA GE THE OR Y OF PR O TEID DIGESTION. 40 7 
Now washed with water until no reaction for chlorides was obtained, and 
afterwards treated with alcohol and ether, it formed a powder of slightly 
yellowish colour. A part of this purified antialbumid was dissolved in sodium 
carbonate solution of '5 per cent., and treated with a dialysed and very active 
trypsin solution at 37°-38 C. After thirty minutes the mixture began to be 
turbid, and in two hours solidified to a clot. By breaking up the clot and 
filtering, the fluid part was separated from the clot; it was made scarcely 
turbid by neutralisation, and yielded by further digestion no new precipitate, but 
contained a fair amount of peptone. 
The separated clot was soluble in hydrochloric acid of 2 per mille, but as 
insoluble in sulphuric acid of 4 per mille as the original precipitate. It was 
completely precipitated from solution in 1 per cent, sodium carbonate solution 
by concentrated sodium chloride solution. From this it seems that in the 
coagulation of albumid in trypsin no change takes place other that its becom- 
ing more insoluble in sodium carbonate solution. The action of trypsin in 
more alkaline solution was next tried; after the first precipitation of the 
albumid it was dissolved in '75 per cent, sodium carbonate solution, digested 
with dialysed tryptic fluid, neutralised and filtered. The clotlike albumid was 
dissolved in 5 per cent, sodium carbonate solution, and by repeated digestion 
with dialysed tryptic fluid, the greater portion was converted into antipeptone. 
The final residue from this much accentuated tryptic digestion was completely 
insoluble even in 5 per cent, sodium carbonate solution, but dissolved in 1 per 
cent, caustic soda. Precipitated by neutralising with hydrochloric acid, 
washed, redissolved in sodium carbonate, and treated with trypsin anew, it was 
again completely thrown out as a clotlike coagulation. No leucine or tyrosine 
was present in the tryptic filtrates. 
How widely this account differs from the statement which occurs in 
most text-books, that antialbumid is not attacked by pepsin, but is 
converted into antipeptone by trypsin, may easily be seen. In a fluid of 
equal alkalinity to that found in the body, antialbumid is no more 
digested by trypsin than it is by pepsin and hydrochloric acid. Now 
it has been shown that trypsin is most active in a sodium carbonate 
solution of about 1 per cent., 1 and considerably less active in one of 5 
per cent. ; why then does trypsin in 5 per cent, solution do that which it 
is unable to do in 1 per cent, solution ? Obviously because the 5 per 
cent, solution dissolves the clot of antialbumid, while the 1 per cent, 
solution does not. In the former case a weaker trypsin acts on anti- 
albumid in solution ; in the latter, a stronger trypsin on antialbumid as 
an insoluble precipitate. 
Be this as it may, antialbumid is only with great difficulty and 
incompletely peptonised by trypsin. In all its properties, from its mode 
of formation onward, the substance appears to be merely a very insoluble 
form of acid albumin. 
Antialbumose. — By a fractionated peptic digestion, Kiihne and 
Chittenden 2 obtained a substance which they termed antialbumose. 
The preparation of this substance from white of egg is as follows : — 
The white of fifty eggs was freed from membrane, diluted and coagulated 
by boiling after acidifying with acetic acid. The coagulated proteid was 
digested in two litres of 4 per mille hydrochloric acid and one litre of dialysed 
gastric extract for one and a half hours at 40" C, it Avas then allowed to cool 
to the temperature of the room and filtered from the undissolved part, the 
process of filtration occupying two days. The undissolved residue was again 
treated with fresh gastric extract until it was all dissolved, which occupied 
1 See p. 338. - Loc. eit., p. 171. 
