SCIENTIFIC SEMMART. 
207 
February. — On the Classification and Arrangement of Microscopic Objects. 
By James Murie, M.D., F.L.S. — Immersion Objectives and Test 
Objects. By John Mayall, Jun., F.B.M.S. — Notes on Mounting Animal 
Tissues for Microscopical Examination. By H. Charlton Bastian, M.D., 
F.R.S. — Some Undescribed Bhizopods from the North Atlantic Deposits. 
By G. C. Wallich, M.D., F.L.S. — On the Construction of Object-Glasses. 
By F. H. Wenham. — The Organ of Hearing in Mollusks. By M. 
Lacaze-Duthiers. — On a New Infusorium. By J. G. Tatem^ F.L S. 
March. — The Address of the President of the Royal Microscopical Society. 
— The Composite Structure of Simple Leaves. By John Gorham, 
M.R.C.S. — On the Construction of Object Glasses for the Microscope. 
By F. H. Wenham. — On a New Growing Slide. By C. J. Muller. — 
On Triarthra Longiseta. By C. T. Hudson, LL.D. — Professor Owen 
on Magnetic and Amcebal Phenomena. By Lionel S. Beale, M.B., F.R.S. 
Had the Fellows of the Royal Microscopical Society continued the old 
journal, they would have been furnished during the quarter with about 
>eleven articles, and 112 pages of letter-press. Under the new organisation 
they have received their reports monthly^ they have been supplied with tioenty 
■original communications, and they have received exactly 196 pages of matter. 
Preparing Sections of Teeth. — The following formula is given by Professor 
Cutler in the American Dental Register. Procure a fresh pulp, and at once 
split it open from end to end ; then lay it on a slip of glass slightly coated 
with balsam pitch, and spread it out, after slightly rounding the glass (some- 
thing like a hunter stretches his coon skin on a barrel to dry) ; then remove 
as much of the cell contents as convenient, by washing with a piece of 
sponge and acetic acid or ether,, rubbing lengthwise with pulp. This will 
show more clearly the septum of filaments, and also show the countless 
openings through the pulp membrane, where the fibrils pass out into the 
dentine. These specimens will not keep well for permanent use, unless 
mounted in pitch on both sides \ even then changes take place. 
A Substitute for a Nose-piece is thus described by Mr. James Vogan, in 
Science Gossip for January, but we do not think it will be found very useful, 
viz.; Divide the circumference of the screw, both of the ^^object-glass” and 
body,” into four equal parts ; then file away all the thread in two opposite 
quarters, leaving the remaining two opposite quarters intact. It is better 
in practice to remove slightly more than one-fourth on each side, so as to 
allow free clearance. The object-glass may now, by placing it so that the 
remaining portions of thread come opposite the corresponding gaps, be 
passed into the body, right up to the shoulder, without turning it round at 
all; and about one-eighth of a turn fixes it in its place as firmly as if screwed 
in. The adoption of this plan does not prevent the use of the altered object- 
glasses with other instruments, nor does it preclude the use of unaltered 
object-glasses with altered bodies. 
Hoiu to Count the Lines in Nobert's Plates. — The following method is given 
in a late number of Silliman's Journal of Science. If a cobweb micrometer 
is used, the micrometer eye-piece should be firmly clamped in a stand 
screwed to the table, so that the eye-piece is close to the end of the micro- 
scope-tube, but does not touch it — a piece of black velvet being used to 
VOL. VIII. — NO. XXXI. P 
