104 
POPULAR SCIENCE REVIEW. 
object-glass, so as to bring the image of the scale into a focus accurately co- 
incident with the divisions of the stage micrometer. The actual size of the 
miniature scale can be read off upon the stage micrometer, which im- 
mediately gives the amount of diminution, and therefore of the enlarge- 
ment. 
Microscopical Papers of the Quarter. — The following is a list of all the 
papers on microscopic matters which have appeared in the “ Monthly 
Microscopical Journal” during the past three months, October, November, 
and December: — Bog Mosses.” By B. Braithwaite, M.D., F.L.S, 
Reply to ^ Further Remarks on Tolies’ |th and Powell and Lealand’s Im- 
mersion j\th.’ ” By Dr. J. J. Woodward, U.S. Army. *‘On the History, 
Histological Structure and Affinities of Nematophi/c^is Logani, Carr. {Proto- 
taxites Loganiy Dawson), an Alga of Devonian Age.” By Wm. Carruthers, 
F. R.S., &c. ‘‘ On the Active Part of the Nerve Fibre, and on the Probable 
Nature of the Nerve Current.” By Lionel S. Beale, Fellow of the Royal 
Society, and of the Royal College of Physicians, Physician to King’s College 
Hospital. On the Regeneration Hypothesis.” By Dr. Louis Elsberg, of 
New York. On the Use of Monochromatic Sunlight, as an aid to High- 
power Definition.” By Dr. J. J. Woodward, U. S. Army. “One of our 
Common Monads.” By Professor Albert H. Tuttle. “ Is Pedalion a 
Rotifier .P” By C. T. Hudson, LL.D. “ On the Structure and Development 
of the Crow’s Skull.” By W. K. Parker, F.R.S. “ Remarks on the Reso- 
lution of the Nineteenth Band of Nobert’s Plate, by certain Objectives, 
especially by a new Tolies’ Immersion y\th.” By Dr. J. J. Woodward, 
U. S. Army. “Aperture of Object-glasses.” By F. H. Wenham. “Des- 
cription of the Plates Illustrating Mr. W. K. Parker’s Paper on the 
Development of the Crow’s Skull.” “ Proposal for a Standard of Com- 
parison of the Magnifying Powers of Compound Microscopes.” By J. E. 
Ingpen, Esq. “ On the Structure of the Valves of Pupodisctis Argus and 
Isthmia Enervis, showing that their Silicious Deposit conforms to the 
General Plan of Deposition in Simpler Forms.” By Henry J. Slack, F.G.S., 
Sec. R.M.S. “ Notes on the Development of the Nervous System of the 
Annulosa.” By B,. T. Lowne, M.R.C.S., F.L.S., Lecturer on Physiology at 
Middlesex Hospital Medical School. “ Notes on New Acarelli.” By J. G. 
Tatem. “ On a Proposed Standard Micrometer Eye-piece, or Eidometer ; 
and on a Uniform and Easily Applied Method of Naming Microscopic 
Objectives.” By George Findley. “ On a Method of Ascertaining Magni- 
fying Power and Minute Magnitudes by Miniatures. By Dr. Royston- 
Pigott, M.A.,M.D. Cantab., M.R.C.P., F.C.P.S.,F.R.A.S., M.R.I., F.R.M.S., 
late Fellow of St. Peter’s College, Cambridge. “ On a Method of Estimat- 
ing the Optical and Actual Thickness of Microscopic Covering Glass.” By 
G. W Royston-Pigott, M.A., &c. 
PHYSICS. 
Passage of Heat-rays through Inclined Diathermanous Plates. — This is the v 
title of a valuable physical paper, by Professor Knoblauch, in a late number 
of “ Poggendorflf’s Annalen.” It is, however, abstracted in the “ Chemical 
