THE. MICROSCOPE.. 28S 
which has been put forward by an eminent physiologist, loses 
much of its startling character. Currents similar to those of the 
hairs of the nettle have been observed in a great multitude of 
very different plants, and weighty authorities have suggested 
that they probably occur in all young vegetable cells. If such 
be the case, the wonderful noon-day silence of the tropical forest 
is, after all, due only to the dullness of our hearing; and could 
our ears catch the murmer of these tiny maelstroms, as they 
whirl in the innumerable myriads of living cells which consti- 
tute each tree, we should be stunned, as with the roar of a 
great city — Hurley. 
MiC ROS Ory. 
DissECTING KNIVES.—The delicate blades of small dissecting 
knives are liable to become injured, if the instruments are not 
carefully cared for when nct in use. I find, says Prof. H. M. 
Whelpley, that a small piece of thick blotting paper can be slip- 
ped over the blade like a sheath toa sword. If the knife is 
dipped in vaseline before putting it away there will be no danger 
from rust. 
FIXING OBJECTS TO THE COVER GLASs.*—Dr,. Von Sehlen fixes 
samples of fluid or any non-viscous matter to cover-glasses by 
means of albumen. The albumen mixture is made by mixing 
the white of an egg with an equal quantity of cold saturated 
boracic acid solution (about four per cent. of the acid). If after 
being kept, a precipitate is thrown down, the solution is cleared 
by filtration. 
The solution is merely dropped on the cover-glass, and some 
of the material is intimately mixed with it. An even layer is 
then made in the usual manner, and the cover-glass dried in the 
air and fixed in the flame. 
TO DISTRIBUTE DIATOMS ON THE COVER GLAss.—In the Journa 
de Micrographie, M. B. de Langibaudiére suggests the following 
method of distributing the Diatoms over the cover. Several 
drops of distilled water are placed on a cover-glass which has 
been previously laid upon a metal table. The Diatoms are pre- 
served in alcohol, and a drop is removed and allowed to fall into 
*Journ. R. M.S. From Centralb. f. Bakteriol, u. Parasitenk. ~ 
