SCIENTIFIC SUMMARY. 
443 
considerable interest, have appeared in the July, August, and September 
numbers of the “ Monthly Microscopical Journal ” : — 
Synopsis of the Principal Facts elicited from a series of Microscopical 
Researches upon the Nervous Tissues. By Dr. H. D. Schmidt, of New 
Orleans, La. — On Bog Mosses. Bj 7 R. Braithwaite, M.D., F.L.S. — The 
Optical Quality of Mr. Tolies’ |th Objective. By Robert B, Tolies. — On 
the Structure of Diatoms. By O. W. Morehouse, U.S.A. — The Pre- 
sence of Balbiani’s Nucleus in the Ovum of Osseous Fishes. By Dr. 
Yan Bambeke. — Observations on the Tolies’ ^th. By R. B. Tolies,. 
Boston, U.S.A. — On the Nervous System of Actinia. By Professor P.. 
Martin Duncan, M.B., Lond., F.R.S., &c. — On Diapedesis ; or, the 
Passage of Blood-corpuscles through the Walls of the Blood-vessels, 
and how to observe it. By Joseph Needham, F.R.M.S. — On the Morbid 
Growths from a case of Osteoid Cancer of the left Femur. By Joseph 
Needham, F.R.M.S., London Hospital. — Discussion of the Formula of 
an Immersion Objective of greater Aperture than corresponds to the 
Maximum possible for Dry Objectives. By Mr. R. Keith. — Final Re- 
marks on Immersion Apertures. By J. J. Woodward, Assistant-Surgeon 
U.S. Army. — Refracting Prism for Binocular Microscopes. By F. H. 
Wenham, V.P.R.M.S. — On the Value of High Powers in the Diag- 
nosis of Blood Stains. By Joseph G. Richardson, M.D., Lecturer on 
Pathological Anatomy in the University of Pennsylvania, and Micro- 
scopist to the Pennsylvania Hospital. — An Account of certain Organisms 
occurring in the Liquor Sanguinis. By William Osier, M.D. 
PHYSICS. 
Some Curious Experiments in Sound. — Mr. A. M. Mayer gives an interest- 
ing paper, entitled “Experiments in Acoustics,” in “Silliman’s American 
Journal ” for August. For example, he says if we take an Ut 3 fork and 
vibrate it near the ear, and closely apprehend the character of its sound, we 
shall experience a sensation which certainly does not contain that corre- 
sponding to the higher octave of the fork. Now, press firmly the foot of the 
fork against the zygomatic process, close to the ear, directing the foot of the 
fork somewhat backward, and we shall distinctly hear the higher octave of 
the fork singing in concert with its real note. If the auditory canal be now 
closed by gently placing the tip of the finger over it, we shall perceive the 
higher octave with an intensity almost equal to that of the fundamental 
note. The same sensation, though less intense, may be obtained by placing 
the fork on any part of the temporal bone. One can also perceive distinctly 
the higher octave when the fork is placed on the parietal bone, about two 
inches in front of and an inch or so to the side of the foramen, and its foot 
directed toward the opposite inner ear, while the auditory canal of this ear 
is gently closed with the tip of the finger. But the higher octave sings out 
with the greatest intensity when the foot of the fork is placed on the tragus 
of the outer ear. A friend, who is a musician as well as a physicist, re- 
peated these experiments, and he informs me that when the foot of the 
