90 



nearly all, attempts to separate the enzyme from the accompanying 

 protein, the result has been a destruction of enzymic power. Again, 

 when in our manipulation of the enzymes we alter or destroy the 

 character of the proteids which are associated with them, we alter or 

 destroy the character of the enzyme. While it cannot be said that 

 the enzyme and the proteid are identical, we must admit that the en- 

 zyme and proteid are most closely associated 



We have abundant authority to show that diastase is associated wit'n 

 leucosin ; rennin is associated with hetero-proteose ; bromelin appears 

 in close relation to two forms of proteids, and so on through the list 

 a close association of the enzyme with a proteid body can be shown. 

 But it cannot be said that the proteid is actually the enzyme. So far 

 as our present knowledge goes, an analysis of the prot-^id must stand 

 for an analysis of the enzyme. 



From the examination of the water-soluble contents of the latex of 

 the papaw, we may t each the conclusion that the enzyme is associated 

 with one or more of the soluble proteids. An analysis of these p'O- 

 teids bodies was therefore made, as follows : 



For the purpose of analysis, a portion of the air-dried latex was ex- 

 tracted with alcohol, benzine and ether, to remove waxes, resins, etc., 

 the residue consisting of the proteid matters and ash. This prepara- 

 tion is marked I. in the accompanying table. 



A second preperation was made by extraction of the milk, as above, 

 the product dissolved in water and the proteids precipitated by sodium 

 chloride, and the precipitate partly freed from excess of salts, by dia- 

 lysis. 



This process was repeated with a view of obtaining an approxi- 

 mately pure preparation, mid one representative of the enzyme of the 

 latex. This preparation is marked II in the accompanying table. 



Papaw Proteids. 



I. II. 



Air-dry Per Cent. Per Cent. 



Carbon .. 39-96 42-81 



Hydrogen .. 6 57 6-77 



Nitrogen .. 1126 10-08 



Ash, or mineral matter . 9-88 6-51 



Moisture (loss at 100-105°C.) .. 10-83 7-90 



Moisture-free. 

 Carbon .. 44-81 46-84 



Hydrogen .. 6-00 6-39 



Nitrogen 



12 62 10-95 



Ash .. 11-07 7 06 



Moisture-free, ash-free. 



Carbon .. 50-38 50-01 



Hydrogen .. 074 6-87 



Nitrogen .. U1^9, 11 -7^ 

 Oxygen 



28-69 31-34 



100-00 100 00 



The large proportion of mineral ash in the purest preparation — II — 

 is notable and seems to indicate that the proteid constituents and the 

 ash are most closely associated. Otherwise, we may observe that the 

 carbon stands in about the same proportion as in other vegetable pro- 



