494 Green . — The A leohol-producing 
added some of the same solution of cane-sugar to compare 
the behaviour of the ground and unground yeast. In this 
control, a certain amount of gas appeared after a while, but 
it was much longer in being generated, and the amount was 
much less than in the other case. 
I transferred the paste in a stone mortar to a refrigerator, 
in which I left it all night. The next morning the paste had 
become very porous, and had risen like so much dough, 
forming a dome-shaped mass nearly three times as large 
as the original volume of the paste. The control did not 
show at all an equal activity. 
The paste was then wrapped up in a piece of fine sail-cloth 
and submitted to pressure. It was first squeezed in a screw- 
press, the weight being added very gradually till it reached 
5-7 atmospheres per square inch. About 80 cc. of a yellowish 
liquid were thus extracted. It was then transferred to a 
hydraulic press, and the squeezing continued till a weight 
of about 500 atmospheres per square inch was applied to it. 
This great pressure only extracted about a further 1 5 cc. 
My preparation so far agreed with Buchner’s in the method 
of obtaining it, but the quantity of extract was very much 
less than his. I did not recover even all the extracting 
liquid, probably owing to loss by evaporation during the 
night. 
The two extracts were kept separate during the further 
operations. Both were shaken up with a little kieselguhr 
and filtered through fine Swedish filter-paper. The resulting 
liquid gave the same reactions as Buchner has described for 
his own preparations. 
Both before and during the filtration the extract was giving 
off small bubbles of gas, which formed a ring round the edge 
of the liquid in contact with the beaker. 
I ascertained by microscopical examination that the filtrate 
was free from yeast-cells, and then I added to the 80 cc. of 
the first (lightly pressed) extract 50 cc. of a solution of cane- 
sugar of 40 °/ o concentration. I put this mixture into a flask 
fitted with a mercury manometer; and to protect it from 
