49 2 Green . — The Alcohol-producing 
paring an extract which agreed in most particulars with his, 
my results were distinctly opposed to his as regards the 
existence of an enzyme. The liquid had the odour and 
the specific gravity of Buchner’s, answered the same chemical 
tests, and deposited a heavy proteid coagulum in heating 
to 45°-5o°C. It would not, however, set up even a small 
evolution of C 0 2 when kept in contact with solution of cane- 
sugar at any temperature, nor would it manifest any other 
sign of the desired activity. It was capable, on the other 
hand, of inverting cane-sugar, and it digested its own proteids. 
As a result of my inquiry made upon resting yeast under 
these conditions, I came to the following conclusion, which 
was given in my paper : — ‘ For the present, therefore, I must 
contend, in opposition to Buchner, that at any rate our 
English yeasts do not contain any alcohol-producing enzyme.’ 
My researches during last year were made, as I have 
already said, upon yeast in the resting condition. During 
the present year I have carried out further experiments to 
supplement the former ones, and have worked with yeast 
taken for extraction at the moment of its greatest activity. 
I obtained, through the kindness of Messrs. Combe & Co., 
a sample of a pure culture of Saccharomyces Cerevisiae from 
Hansen’s laboratory. I cultivated this in beer- wort in an 
incubator, using about a kilogramme. The fermentation was 
conducted at a temperature of so 0 C., and after a few hours 
it was very vigorous, the liquid frothing very energetically. 
While it was at its height, I removed the yeast from the 
wort, and rapidly strained it through a calico filter. The 
resulting pasty mass was then subjected to pressure in a 
screw-press till it was dry enough to crumble between the 
fingers. So prepared, the kilogramme of moist yeast 
originally employed weighed ioo grammes. 
I had found in my former experiments that it was very 
difficult to grind the yeast-cells in the presence of sand, the 
latter being coarse enough to protect them from contact 
with the grinding surfaces : I therefore used no sand in the 
next stage of the process. Instead, I mixed the nearly dry 
