Monthly Microscopical) —- Royal Microscopical Society. 5 
first, whereas in the other it was simultaneously occupied by a variety 
of organisms.* 
A cold-water extract of barley meal also possesses the property 
of converting cane sugar into mucilage, but the yeast cells soon 
develop, and resolve the greater portion of it into alcohol and car- 
bonic acid gas. This is a most interesting phenomenon, and it 
serves to convey some idea of the wonderful power and singular 
properties of the yeast plant. 
Under the microscope the yeast cells can be seen in the muci- 
laginous mass, sometimes in bundles resembling a bunch of grapes, 
and sometimes in a chain-like form, and also that the multiplication 
of the cells is carried on by a process of budding, Plate LY., Fig. 5. 
This mucilaginous form of solution will afford an excellent op- 
portunity of studyimg the development and growth of the yeast 
plant, and be the means of finally settlmg the question as to its 
true vegetable origin. Cane sugar is not converted into mucilage 
in all extracts prepared from barley meal. In a great many cases, 
especially at this season of the year, and under the influence of a 
high temperature, the yeast cells begin to act soon after the pre- 
paration of the extract and counteract the formation of mucilage. 
The formation of mucilage is also prevented if, before the 
addition of the sugar, the extract is boiled for about half an hour 
in order to destroy the microscopic animals present. 
In cold-water extracts of malt, to which cane sugar has been 
added, the cane sugar is not converted into mucilage, as in the case 
of barley meal and wheaten flour extracts. There is at first a slight 
tendency to thickening, but there appears to be an opposing action 
set up in the malt extract which prevents the formation of mucilage. 
With malt extracts prepared in the cold very fair fermentations 
can be obtained; but as the samples are primarily occupied by 
a variety of organisms, a large percentage of acid is produced, and 
considerable loss of alcohol sustained. 
The results hitherto obtained point to the microscopic animals 
as being the proximate cause of both the transformation of cane 
sugar into mucilage, and the production of acid; and the change 
effected in the sugar especially tends to the inference that the 
action is a catalytic one. It is hardly possible to believe that these 
creatures could have devoured so large a quantity of sugar in so 
short a time, or that having devoured it they would have reproduced 
it in a mucilaginous form. 
Moulds and Pus.—A few experiments have been made with 
certain moulds, and one with pus, to determine their respective 
actions in sugar solutions. 
The study of the development and properties of moulds, like 
* There has been a considerable difference observed in the number of animals 
and germs present in different samples of malt. 
