102 
POPULAR SCIENCE REVIEW. 
MICROSCOPY. 
Browning's neio Non-vibratory Microscope . — Mr. Browning lias just brought 
out an instrument, the plan of which has been some time in use on the Con- 
tinent, and which was in this country devised by Mr. Mayall, jun. Many 
plans have been tried for getting a revolving stage which should have its 
centering perfect, but they have almost always failed. In the present 
instance the stage and body are made in one piece, so that they revolve 
together, thus preventing any absence of complete centering, for of course 
the focus cannot be altered in even the slightest lateral direction. When 
first we saw the instrument we were under the impression that it could 
with difficulty be made in any binocular form, but this difficulty has been 
completely got rid of by Mr. Browning, who has already made several of 
this variety of instrument of the binocular kind. 
Valuable Researches on the Monads. — Decidedly the best investigations of 
these creatures that have ever been conducted are those now being made and 
published in the “ Monthly Microscopical Journal ” for December. The 
authors of the paper describing them are the Rev.W. H. Dallinger, F.R.M.S., 
and Dr. Drysdale. Of one form which they have dealt with they say : — 
“ We had thus gathered up the threads and completed the life-history. 
The usual method of multiplication is by fission, which goes on apparently 
to exhaustion. Amongst enormous numbers there are a few distinguished 
from the others by a slight increase in size and the power to swim freely. 
These become still — for a time amoeboid — then round ; a small cone of 
sarcode shoots out, dividing and increasing into another pair of flagella. 
The disk splits — each side becomes possessed of a nuclear body, and two 
well-formed monads are set free. These swim freely until they attach them- 
selves to an ordinary form that has just completed fission, so that the nuclei 
are approximate. Sarcode and nuclei melt into each other; the form 
becomes free-swimming and' triangular in shape — rests — loses its flagella ; 
becomes clear and distended ; then bursts at the angles, pouring out in- 
describably minute granules, from which myriads of new forms arise and 
repeat the cycle.” 
On the Use of Naphthalin in Section Cutting. — Mr. John Barrow read a 
paper on this subject before the Manchester Literary and Philosophical 
Society. - He said : — “ I wish to bring before the notice of the members, 
and those microscopists who are interested in cutting sections of soft or 
delicate tissues, the use of naphthalin as a support for such tissues in the 
section cutter. The advantages obtained by the use of naphthalin over wax 
and other bodies recommended for this purpose are — A low fusing-point, 
absence of contraction in the cutter, very little injury to the edge of the knife, 
and very ready solubility after cutting in benzol or spirit, so that the sub- 
stance is removed at once from the section without injury. Naphthalin is a 
body not very generally known outside the works of the tar-distiller or 
colour-maker, so that possibly some of the members may not be able to 
obtain samples readily, but I shall have pleasure in supplying it to any of 
our own members .” — u Chemical News,” October 31st. 
