396 
NATURE 
| March 16, 1871 

and upon it a soap-bubble blown from a pipe was thrown ; the 
bubble was caught by the film, and held suspended midway or 
along the equator of the thin hollow sphere. The bubbles were 
then forced through and drawn through without rupture of the 
films. An orange was dropped, and glass rods and other solid 
objects, with wetted surfaces, were passed in like manner without 
rupture of the films. 
The three experiments by Mr, Cromwell F. Varley were 
exhibited for the first time in public. Two of them were 
in illustration of some investigations into the nature of electric 
discharges through gaseous media, described in a paper read 
before the society in January. In a Geissler’s tube, con- 
taining highly rarefied hydrogen, a small filament of tale was 
hung by a single horizontal fibre of silk. Twoaluminium rings, 
separated an inch and a quarter, formed the electrodes inside the 
vacuum. This tube was placed longitudinally with and over the 
horizontal poles of a large very powerful iron horse-shoe electro- 
magnet, made of a bar four inches in diameter and four feet in 
l.ngth, and wrapped with nearly 2 cwt. of thick copper wire. 
A small induction coil sent electric discharges from one ring to 
the other, producing a brilliant blue light around the negative 
pole, the positive pole being dark. The moment the magnet 
was charged, by means of thirty cells of Grove’s nitric acid 
battery, each cell containing twenty square inches of platinum 
foil, the electric luminosity in the tube, which beforehand was 
diffused, gathered up into an arch extending one and a halfinches 
beyond each ring, forming altogether a well-defined arch about four 
inches in length. This luminous arch follows exactly the course 
of those magnetic rays which traverse through the negative pole. 
By shifting the tube the piece of talc can be brought at pleasure 
in or out of this luminous arch. Neither the electric action nor 
the magnet Zev se produce any motion upon the tale ; but whenthe 
tube is so placed that the luminous arch strikes against the tale the 
talc is repelled as much as 30° from the perpendicular. The 
electric current is passing simply from one ring to the other inside 
the tube, but the luminous arch in question where it strikes the talc 
is on the other side of the ring and where no electricity is flowing. 
Mr. Spottiswoode’s musical vibration experiment consisted of 
the visiblerepresentation of the formsactually assumed bya musical 
string when producing a note or its harmonies. To show this it 
is required that the string should be kept in a perfectly uniform 
state of vibration. This was very ingeniously accomplished by 
means of tuning forks kept in vibration by electro-magnets, these 
forming their own breaks in cups of mercury. 
The singular action of nuclei in promoting crystallisation has 
long been known, bu' recent experiments by Mr. Chandler Roberts, 
chemist of the Mint, have imparted additional interest to the sub- 
ject. Minute traces of lead, antimony, bismuth, or arsenic, render 
the alloy of gold and copper known as “ standard gold” crystal- 
line, intensely brittle, and totally unfit for the purpose of coining. 
This remarkable effect is produced even when the amount of ob- 
noxious metal does not exceed the ys, part of the mass of 
standard gold. Mr. Roberts exhibited beautiful specimens of 
crystalline standard gold and illustrations of the process of tough- 
ening brittle gold by means of chlorine recently introduced in the 
Mint, the adoption of which has afforded a satisfactory solution 
to a question of considerable importance connected with the 
manufacture of coins. 



SCIENTIFIC SERIALS 
THE Mittheilungen der naturforschenden Gesellschaftin Bern for 
1869, published last year, contain may important papers.— 
M. E. Schir publishes a valuable contribution to the knowledge 
of some cyanogen compounds, and a memoir of considerable 
length on peroxide of hydrogen, and its relations to ferments.— 
M. A. Gruner communicates a short but interesting paper on the 
luminosity of the so-called ‘‘touchwood,” in which he details 
several experiments, and comes to the conclusion that ozone is 
to be regarded as the principal cause of the phenomenon.—In 
geology we find some valuable memoirs by M. C. von Fischer- 
Ooster, especially a paper on the Rheetic stage in the neighbour- 
hood of Thun, which includes an account of the beds, and a list 
of the fossils occurring in them, with descriptions of some new 
species, and many figures. The same author also contributes 
several smaller papers on the occurrence of a Liassic zone 
between the chain of the Moleson and the Miremont in the 
Canton of Freiberg, on the narrow Flysch zone from the 
Hongrin towards Jaun, on the geological age of the so-called 
Tavigliana Sandstone, and on the stratigraphical conditions near 
the Kiiblisbad.—M. J. Bachmann publishes some remarks in 
opposition to M. Renevier’s geological observations on the Alps 
of Central Switzerland compared with the Vaudoise Alps, and 
M. A. Rytza notice on the erratic formations in the Kander- 
thal.—M. Theophil Studer notices the occurrence of Foramini- 
fera in the Alpine chalks, detected by the examination of thin 
slices, and also describes a new Swiss form of the genus 77of7- 
donotus, {or which, however, he does not venture to propose a 
specific name.—Dr. R. Henzi reports upon the attempts made 
by him to cultivate Saturnia Mylitta and S. yama maya, and 
M. G. Hasler describes and figures an apparatus for giving 
telegraphic intimation of the height of water in reservoirs, &c. 
—The Proceedings of the society also contain short notices upon 
various subjects. 
THE Atti della R. Accademia delle Scienze di Torino for the first 
six months of the year 1870 (vol. v. parts 3—7) contains 
numerous papers on various branches of science, but principally 
on subjects connected with physics. Of zoological memoirs we 
have a notice of some new and iittle-known species of birds 
collected on the voyage of the A/agenta by MM. Giglioli and 
Salvadori, the new species being Acridotheres leucocephalus and 
Leptoptila chlorauchenia ; a paper by Dr. Giglioli on the phos- 
phorescence of the sea, with notices of the various animals 
observed by him to be luminous, and descriptions of two new 
species of the genus WVoctiluca (NV. omogenea and N. pacifica) ; 
descriptions of new species of birds by M. Salvadori, namely, 
Saxicola allo-marginata from the Sahara, S. Brehmii from 
Nubia and Abyssinia, Brachypus urostictus from the Philippines, 
and the type of a new genus allied to alacopleron, Homo- 
chlamys luscinia (Finsch MS.) from the Philippines or China ; 
anda critical revision of Antinori’s descriptive catalogues of birds 
collected by him in North Central Africa.—M. Cavalli, in a 
memoir on a gunpowder uninjurious to cannon, maintains the 
superiority of large grains, especially if made spherical and more 
regular and hardened at the surface.—A new form of mercurial 
barometer is described by M. Faa di Bruno, and the barometric 
formula of Count Paolo de Saint-Robert is discussed by Prof. 
Dorna, who also presents what he calls a loghypsometrical table 
for use in applying the barometric formula worked out by him in 
the determination of altitudes.— Prof, Govi describesa new 
method of obtaining sensitive flames, consisting in the applica- 
tion of a wire net with meshes about one millim. square to an 
ordinary gas jet, and lighting the gas after its passage through 
the meshes. The same author also publishes a note on the 
influence of sonorous vibrations upon cold and ignited gas jets. 
—Prof. Boccardo notices the fall of an earthy shower at Genoa 
on the 14th February, 1870. He gives an analysis of the 
material, which consisted chiefly of sand with oxide of iron 
and carbonate of lime, and contained 6611 per cent. of 
nitrogenous organic matter. Under the microscope, it was found 
to contain frustules of Diatomacez and fragments of other simple 
Algze. No windstorm had occurred immediately before the fall of 
the shower, which the author considers to have probably come 
from Egypt.—Prof. Dorna has a note on the scientific importance 
of Soperga and the Sacra di San Michele to the Observatory of 
Turin, and upon their respective differences of level. —M. Richelmy 
communicates some notes on the construction and operation of 
toothed wheels.—In a paper on nitroglycerine, nitromannite, 
and pyroxyline, Prof. Sombrero vindicates his tide to be regarded 
as the discoverer of the first of these compounds, and notices the 
properties and mode of preparation of the other two. M. L. F. 
Menabrea furnishes some explanations of his views on the prin- 
ciples of elasticity, which are disputed by MM. A. Parodi and 
G. Barsotti. M. Codazza describes an apparatus devised by him 
to act as an electrical indicator to give notice of the attainment 
of the maximum or minimum limits of temperature between 
which it is required to keep any substance. Prof. Denza de- 
scribes an aurora borealis observed in Piedmont on the 5th April 
1570.—Prof. Govi indicates that Thenevot was the inventor of 
the spirit-level with a bubble of air. The same author communi- 
cates a paper by Prof. Chid ona barometric formula.—M. Gastaldi 
notices a collection of stone weapons and instruments from the 
neighbourhood of the Baltic, and also some ancient weapons and 
instruments of stone, bronze, or brass, from Egypt. Several of 
these are figured ; one of them, a long, chisel-shaped, bronze 
instrument, is attached obliquely to a mallet-shaped handle, in 
such a manner as to serve as a small axe.— Prof. Luvini publishes 
a long paper on the adhesion between solids and liquids.—M, 
Genocchi notices some papers ascribed to A. Cauchy.—Prof. 
Dorna describes the instruments and methods employed at the 
Observatory of Turin for the measurement of time,—M, A. 

eee ee 
