CHAP. II.] 



AXTIALBUMOSE. 



123 



Antialbumose. 



It has been stated that u ,w,hen .proteids are digested with dilute 

 mineral acids, antialbumat and antialbumid are the only representa- 

 tives of the anti-moiety of the proteid molecule. When Kiihne had 

 discovered in hemi-albumose an intermediate product between proteid 

 and hemipeptone, he was naturally led to surmise that there probably 

 existed an- analogous albumose corresponding to antipeptone. Direct 

 experiment furnished evidence which leaves no doubt, indeed, of the 

 existence of such a body, though it has not been obtained in a condi- 

 tion of purity nor in large quantity. The substance is found in the 

 precipitate obtained by neutralising digestive mixtures of acid pepsin 

 and proteid, but, as follows from what has been already stated, in the 

 neutralisation precipitate, any antialbumose which may be present i& 

 mixed with antialbumat. 



The following account of one of Kuhne and Chittenden's experi- 

 ments, having for its object the separation of antialbumose, will 

 convey an idea of the methods to be employed *. 



The albumin of 50 eggs was treated with water and acetic acid 

 and coagulated by heat. The coagulum having been washed and 

 freed from water, by pressure, was digested in two litres of dilute HC1 

 (0'4 per cent.) at 30 C., mixed \vith one litre of artificial gastric juice 

 at the same temperature. 



The artificial gastric juice had been prepared by digesting for 48 

 hours at 40 C. the whole of the mucous membrane of a pig's stomach, 

 with the exception of that from the pyloric region, in 2 litres of HC1 

 containing 0'4 per cent. After this digestion the liquid had been dialysed 

 for 24 hours in a Kiihne's tube dialyser (see Fig. 7, p. 89), in a stream 

 of running water: salicylic acid in the proportion of one part in 1000 

 having been added before dialysis, and hydrochloric acid being added at 

 its conclusion so as to again bring the amount of acid to the original 

 amount, viz. 0-4 per cent. 



The digestion having proceeded for an hour and a half, the 

 mixture was filtered, so as to separate the considerable quantity of yet 

 undissolved albumin. This was treated with a fresh quantity of the 

 gastric juice ; in 15 hours at 40 C., solution was effected, the quantity 

 of liquid amounting to 600 c.c. The solution thus obtained, after 

 filtration, was neutralised, when a precipitate fell, considerable in 

 amount, yet small in comparison to the amount of albumin operated 

 upon. The precipitate was washed, dissolved in 150 c.c. of gastric 

 juice, digested for 48 hours, and, on neutralising, again precipitated, 

 not appreciably diminished in amount. In this way was obtained a 

 body having the same characters as Meissner's parapeptone. 



This body consisting of a mixture of antialbumose and anti- 

 albumid, was dissolved in solution of sodium hydrate (0*75 per cent.) 

 and digested for about 48 hours at 40" C. with a dialysed pancreatic 

 extract. No clotting occurred. 



1 Kiihne und Chittenden, ' Ueber Albumosen.' Zeitschrift^Ux^BMogie. Vol. xx. 

 (1884). 



UNIVERSITY' 



