602 Vines . — Proteolytic Enzymes in Plants {II). 
exists with regard to the Beet-root, and to the epicarp of the 
Orange. These divergences probably depend to some extent 
upon seasonal differences in the material examined, upon the 
higher temperature which I employed, and perhaps to an 
even greater extent upon the antiseptics used in the different 
experiments. Buscalioni and Fermi used exclusively carbolic 
acid ; whereas I have never done so, but have used chiefly 
hydrocyanic acid or chloroform-water. In subsequent pages 
of this paper, I propose to consider the relation of various 
antiseptics to proteid-digestion in some detail. 
Further, we are in agreement in the general conclusion that 
the vegetable proteases are most active in an acid medium. 
But as regards the products formed in digestion we neces- 
sarily part company : for it was not possible by the gelatine- 
method to obtain the information afforded by the tryptophane- 
method. Buscalioni and Fermi mention, indeed, that in certain 
cases they obtained the biuret-reaction, indicating the presence 
of albumoses or peptones, in the liquefied gelatine, but they 
did not attempt to pursue the subject further. The advantage 
of the tryptophane-method adopted by me, is that it throws 
light upon this fundamental question, and that any kind 
of proteid matter can be subjected to experiment. Whilst 
the gelatine-experiments of Buscalioni and Fermi were the 
first to indicate the wide distribution of proteases in plants, 
my tryptophane-experiments demonstrated that these widely- 
diffused substances are completely proteolytic in action, so 
far as they have been investigated. 
Proteases and Antiseptics. 
I have already suggested that such divergences as exist 
between the observations of Buscalioni and Fermi and my 
own are probably due, at any rate to some extent, to the fact 
that we respectively made use of different antiseptics. This 
suggestion is based on results that I have obtained tending to 
show that the same protease is affected differently by different 
antiseptics, as also that different proteases are diversely 
affected by the same antiseptic. In the following paragraphs 
