ge UE ie a i Royal Microscopical Society. 18 
to ascertain the influence of change of soil upon the development of 
the yeast plant. 
To a solution containing 82°24 per cent. of glucose some albu- 
men of egg and a small quantity of healthy wine ferment were 
added, and the sample was placed in a chamber maintained at a 
temperature of about 67° Fahr. 
The wine yeast cells remained bright and healthy, but did not 
appear to possess much activity; in the course of seven or eight 
days albumen cells were developed, and there was an apparent action 
going on in the liquid. 
At the expiration of nineteen days the sample was examined for 
alcohol, and it was found to contain only -71 per cent., and at the 
end of a month it was again examined and found to contain ‘92 per 
cent. and one-tenth per cent. of acid. 
It was obvious from this result that the soil was unsuited for the 
growth and propagation of the wine yeast cells. The sample was 
now diluted by the addition of water until the percentage of glucose 
was reduced to ‘18 per cent. This change of condition, however, 
had little influence in promoting the action of the cells, and the 
percentage of alcohol at no time afterwards was found to exceed 1°04 
per cent. 
At the end of several weeks a new form of fungoid growth was 
found to have been developed in the liquid and a great mass of fresh 
cells produced, whose action appeared to have completely superseded 
the alcoholic ferment, and when the sample was next examined it 
was found to contain no alcohol whatever, but 2°80 per cent. of 
acid. 
Two malt extracts were prepared, and the glucose present was 
made up in each case to about 30 per cent. To one sample wine 
ferment was added, and to the other malt ferment. The experiments 
were conducted, so far as was practicable, under the like conditions; 
but the results were somewhat different, the proportion of alcohol 
produced in the sample to which the malt ferment had been added 
having exceeded the quantity produced in the other; and it may 
be added that the ‘spirits produced in the samples were perceptibly 
different in flavour. 
Although this experiment is not regarded as conclusive, still it 
is worth recording, as the result tends to the same conclusion as that 
indicated by the results obtained in some of the other experiments, 
in showing that the different ferments have their favourite soils, and 
that they flourish best in those natural to them. 
The results of the experiments would probably bear a more gene- 
ral conclusion in indicating a comparative inactivity of fungoid spores, 
unless when they meet with a soil that is favourable to their growth 
and development. 
