418 CHEMISTR Y OF THE DIGESTIVE PROCESSES. 



cleavage or any other theory, save in the names of such of the substances 

 as have been named on a theoretical basis : 



PEPTIC DIGESTION. TRYPTIC DIGESTION. 



Proteid. Proteid. 



Acid Albumin Alkali Albumin 



_J I 



| | Deuteroalbumose 



Protoalbumose Heteroalbumose [ 



\ / Antipeptone, amido-acids, etc. 



Deuteroalbumose 

 Amphopeptone. 



In the above account of the internTediate products formed between 

 proteid and peptone, an attempt has been made to point out how far 

 each important experimental result is in agreement with, or lends support 

 to, the cleavage theory of proteid digestion. Most of the results have 

 been obtained by supporters of that theory, but these results fall far 

 short of proving the truth of the theory, and may be explained without 

 reference to anti- and hemi-bodies. The main points may here be 

 summarised : 



1. Certain substances have been obtained by the action of dilute acids on 

 proteids, which do not yield amido-acids when subjected to prolonged tryptic 

 digestion; these substances have been on this account looked upon as pure 

 anti-compounds. But there is no evidence that such substances are formed 

 naturally in either peptic or tryptic digestion : there is evidence against it in 

 the extreme difficulty with which they are attacked either by pepsin or 

 trypsin. Neither are these substances in their chemical behaviour albumoses, 

 so that the term antialbumose, as applied to any of them, is a misnomer. 



2. The substance originally obtained from a fractionated peptic digestion, 

 and named hemialbumose, was afterwards shown by its discoverers to be a 

 mixture of three bodies, protoalbumose, heteroalbumose, and deuteroalbumose, 

 and none of these three discrete bodies was found to be either a pure hemi- 

 albumose or pure antialbumose, so that, if the cleavage theory is to be main- 

 tained, we must be content to believe that each of these three is a mixture 

 in varying proportions of anti- and hemi-groups, and admit the existence of 

 antiprotoalbumose and hemiprotoalbumose, of antiheteroalbimiose and hemi- 

 heteroalbumose, of antideuteroalbumose and hemideuteroalbumose, without 

 any experimental evidence whatever. Again, the cleavage theory takes no 

 account of the fact that proto- and /z-eferoalbumose are formed prior to the 

 deuteroalbumose. 



3. Amphopeptone is supposed to be a mixture in about equal proportions 

 of antipeptone and hemipeptone ; but these two bodies have never been isolated 

 from it. Antipeptone can only be obtained from amphopeptone by the action 

 of trypsin, and hemipeptone has never been obtained at all. 



4. There is no doubt that some forms of proteids, or altered proteids, are 

 more easily decomposed by trypsin, yielding amido-acids, than are others ; but 

 this does not prove that such bodies are variable mixtures of a fraction which 

 is not decomposable at all with one which is completely decomposable. When 

 from an ampho-body there have been isolated two fractions, one a pure anti- 

 body that is completely unalterable by trypsin, the other a pure nemi-body 

 that is completely decomposable into amido-acids by trypsin, then it will be 

 time to believe in ampho-, anti-, and hemi-bodies. At present neither from 

 amphopeptone, protoalbumose, heteroalbumose, or deuteroalbumose has there 



