270 
NOTES AND MEMORANDA. 
slide and dried in a warm place (well protected from dust), wliich 
takes about ten or fifteen minutes, A drop of dammar varnisli or 
Canada balsam is added to it, and the covering glass pressed down as 
much as possible. The preparation is then ready. 
As compared with preparations made by Dr. Koch’s method, the 
ground appears a little more coloured. Since, however, the bacteria 
are considerably darker, and as high powers must necessarily be used, 
in which case the colour of the ground causes no inconvenience, the 
method is strongly recommended to those who have a limited time to 
devote to microscopical manipulating.* 
A Miner alogical Microscope. — M. Eenard describes, in the ‘ Bulletin 
of the Belgian Microscopical Society,’ a new microscope intended for 
the examination of microscopic crystals by polarized light. One of 
the leading pecularities of its construction consists in the contrivance 
(apj>arently adopted for economical reasons) by which the objective is 
centered upon the object on a rotating stage. The tube of the micro- 
scoi)e carrying the object-glass is enclosed in a fixed outer tube, which 
is contracted at the upper part so as not to allow of any “ pivoting ” 
of the inner tube at that end. Below the contracted part there is a 
space between the outer and inner tubes, the former being lined with 
parchment, which is pressed against the latter by springs. Through 
the lower end of the outer tube work two screws at right angles to 
each other, which press against the inner tube and move it in two 
rectangular directions (or any intermediate one), so that it can be 
readily brought into the correct position. 
Alcoholic Fermentation. — An interesting series of experiments was 
lately instituted by Herr Muntz, in order to determine whether the 
living cells of the more highly organized plants, when entirely cut off 
from oxygen, are equally able with the cells of fungi to produce 
alcoholic fermentation. For this purpose he experimented with a 
variety of plants, beet, maize, cabbage, chicory, portulacca, nettles, 
&c. From each kind three equally healthy plants were selected. 
One was left in the open air, and the other two were placed, with the 
accompanying soil, under capacious bell-glasses containing an atmo- 
s^diere of nitrogen, the oxygen being removed by pyrogallic acid. 
After a lapse of from twelve to forty-eight hours, they were removed 
from the glasses. One was placed in the open air in order to be 
certain that the power of development was retained after the imprison- 
ment, and the other was cut off above the ground, distilled with water, 
and tested for alcohol. In all cases the plants which had been in an 
atmosphere free from oxygen showed appreciable quantities of alcohol, 
amounting often to a thousandth of the entire weight of the plant, 
while no traces could be detected in the plant which had remained in 
the air during the same time.f 
Alcoholic Fermentation. — M. Berthelot recently published, in the 
‘ Eevue Scientifique,’ what purported to be a copy of some notes (written 
in October 1877), which were found after his death amongst the papers 
* ‘ Zeitsclirift fiir Mikroskopie,’ vol. i. p. 175. 
t ‘ Nature,’ vol. xviii. p. 504. 
