124 MR. E. SCHUNCK ON THE ACTION OF 



with the exception of emulsine, has any eflfect whatever on 

 amygdaline,* and none of the usual ferments, such as yeast, 

 decomposing caseine, albumen, gelatine, or even emulsine, 

 are capable of supplying the place of erythrozym, as far as 

 regards the decomposition of rubian.f These specific effects 

 of emulsine and erythrozym are more characteristic of these 

 bodies than any other property whatever, and serve to dis- 

 tinguish them from one another and from other ferments with 

 more accuracy than any difference in composition, however 

 great. On the other hand, the decomposition of sugar into 

 alcohol and carbonic acid is an effect common to all known 

 ferments. All so-called proteine compounds, such as albumen, 

 caseine, animal membranes &c., when they enter into decom- 

 position, acquire the properties of ferments. When all other 

 circumstances are alike, the processes of decomposition to 

 which these compounds, when acting as ferments, give rise in 

 other bodies, are precisely the same. The species of decom- 

 position varies only according to the particular stage of 

 decomposition of the ferment itself. During the first stage 

 of decomposition they convert starch into sugar ; during the 

 second stage they change sugar into alcohol and carbonic 

 acid, bile into cholalic acid, taurine, and other products, and 

 tannic into gallic acid ; when they have entered on the third 

 stage of decomposition, they effect the conversion of sugar 

 into lactic acid, and of lactic acid into butyric acid, carbonic 

 acid, and hydrogen. All these various effects may be pro- 

 duced by emulsine, provided the latter be in the state of 



* I have mixed amygdaline and erythrozym, and amygdaline and madder 

 itself, together with water, to the consistence of paste, and allowed the mixtures 

 to stand for days in a warm place, without perceiving any signs of the decom- 

 position of the amygdaline ; while a mixture of amygdaline, emulsine, and 

 water, will under the same circumstances, evolve the peculiar smell of oil of 

 bitter almonds in a very short time. 



f Emulsine is indeed not entirely without effect on rubian, but the quantity 

 of the latter which it is capable of decomposing, even after a long lapse of time, 

 is extremely insignificant. 



