406 CHEMISTRY OF THE DIGESTIVE PROCESSES. 
closely resembling Meissner's parapeptone antialbumate ; considering 
them anti bodies, from the fact that they do not yield leucine and 
tyrosine on tryptic digestion, but are, though with difficulty (especially 
in the case of antialbumid), converted into antipeptone. 
Kiihne gaA~e the following graphic representations of the cleavage of 
proteids by acids and by digestion : — 
Scheme of Proteid Cleavage by Acids. 
ALBUMIN. 
Antigronp. ETemigronp. 
Antialbumid. 
Antialbumate. 
Antialbumose. Hemialbumose. 
Antipeptone. Hemipeptone. 
Scheme of Digestive Cleavage of Proteids. 
ALBUMIN 
(Albuminate). 
! 
(Antialbumose. Hemialbumose. 
1 | 
II I I I Tryptic 
Antipeptone. Antipeptone. Hemipeptone. Hemipeptone. Digestion. 
Leucine. Tyrosine. Leucine. Tyrosine. 
Kiihne, in conjunction with Chittenden, 1 subsequently investigated 
more minutely the intermediate products in peptic digestion, and those 
formed by the action of dilute acids. The following is an account of 
the substances obtained and their mode of preparation : — 
Antialbumid. — This substance was prepared as follows : — The -white of fifty 
eggs, freed from membrane and much diluted, was made feebly acid with 
sulphuric acid and coagulated by boiling. The coagulum was suspended in 
1300 c.c. of water containing 7 c.c. of sulphuric acid and heated to 100 u C. : after 
ten hours it appeared little altered and was filtered off. The filtrate gave on 
neutralisation a precipitate principally composed of acid albumin. After 
removal of the first acid, the albumin which had remained undissolved was 
heated with 3 litres of i per cent, sulphuric acid to 100° C. for nineteen hours, 
then collected on a filter and completely washed. 
The albumid thus obtained was insoluble both in dilute and concentrated 
acetic acid, and in hydrochloric acid of 1*4 per mille and stronger, but easily 
soluble in dilute caustic soda solution and in dilute alkaline carbonates, from 
which it was precipitated by concentrated sodium chloride. Purified by diges- 
tion with gastric extract and 4 per mille hydrochloric acid for six hours at 
40° C, it remained undissolved, but changed in appearance, becoming clotlike. 
The clot was washed with water, dissolved in 1 per cent, solution of sodium 
carbonate, filtered, reprecipitated with sulphuric acid, and washed again. It 
now dissolved in 2 per mille hydrochloric acid, and in this solution was digested 
with good peptic extract for eighteen hours. It was unchanged, and reappeared, 
in equal amount to the eye, on neutralisation of the solution. 
1 Ztschr.f. Biol., Munclien, 1883, Bd. xix. S. 159. 
