Feb. 22 1883] 
NATURE 
403 
iron being probably in the so-called ‘‘colloidal” condition. 
Such ferric hydrate is not turned black by sulphuretted hydro- 
gen; ordinary ferric hydrate is turned black at once, and the 
sulphide of iron dissolves in excess of potassium cyanide, form- 
ing potassium sulphide and ferrocyanide.—On alpha cyano- 
naphthalene sulphonic acid, by W. K. Dutt, The author first 
prepared the naphthalene sulphonic acid, then distilled the 
potassium salt with dry potassium ferrocyanide, and converted 
the cyanonaphthalene by sulphuric hydrochloride into the above 
substance. 
The Institution of Civil Engineers.—February 13, Mr. 
Brunlees, president, in the chair. The paper read was on ‘* The 
Design and Construction of Repairing-Slipways for Ships,” by 
Mr, I. B. Lightfoot, M. Inst. C.E., and Mr, John Thompson. 
EDINBURGH 
Royal Society. January 29.—Mr. Thomas Stevenson, 
M.Inst.C.E., vice-president, in the chair.—Dr. Knott read a 
paper by Mr. H. R. Mill on the rainband, being a description of 
the author's observations during the last six months of 1882. 
The observations were all made with Mr. Hilger’s smallest size 
of pocket spectroscope, in which the presence of the rainband is 
indicated only by an apparent broadening of the D line. Mr. 
Mill measured the varying intensities of the rainband by com- 
paring D with the other evident lines in the spectrum—E, 4, F, 
The distinctness of the fine lines in the green was also found to 
be an additional factor in prognosticating the weather ; the less 
distinct these lines the greater the chance of rain, An analysis 
of the observations showed that of the ‘‘rain” predictions 78 
per cent, came true; of the ‘‘no rain” predictions 64 per cent. 
—The Rey. J. L. Blake read his third communication on the 
theory of monopressures applied to-rhythm, accent, and quantity. 
—Mr. John Aitken read a paper on the effect of oil on a stormy 
sea, in which it was proved by experiment that the presence of 
the oil film did not calm the waves, but merely prevented them 
from breaking. The reason given was that the wind had no 
power to produce wavelets on the oil-surface, since in virtue of 
the action of surface-tension any forward motion of a portion of 
the oil-film necessitated the forward motion of the whole. In 
the case of a clean water surface, again, the wind acting strongly 
upon any small surface portion would push it ove the contiguous 
surface, and so give rise to a wavelet. Some beautiful experi- 
ments on the effect of surface-tension were shown as bearing 
upon the subject.—A note was read from the Astronomer-Royal 
for Scotland calling attention to the remarkably high tempera- 
ture maximum which had occurred some time during the 
preceding night. 
CAMBRIDGE 
Philosophical Society, February 12.—The following com- 
munications were made to the Society :—On the isochromatic 
curves of polarised light seen in a uniaxal crystal cut at right 
angles to the optic axis, by Mr. R. T. Glazebrook.—On a spec- 
trophotometer, by Mr. R. T. Glazebrook. The paper descr bes 
an arrangement for viewing simultaneously the spectra formed 
by the light from two different sources after traversing the same 
set of direct-vision prisms. These two spectra are polarised in 
two planes at right angles and {their relative intensity is deter- 
mined by the position of a Nicol in the eye-piece through which 
they are observed.—On a common defect of lenses, by Mr. R. 
T. Glazebrook. The author exhibited some lenses which, when 
placed between two crossed Nicol’s prisms, showed strong 
elliptic polarisation.—On the motion of a mass of liquid under 
its own attraction, when the initial form is an ellipsoid, by Mr. 
W. M. Hicks.—On functions of more than two variables ana- 
logous to Tesseral Harmonies, by Mr. M. J. M. Hill.—Observa- 
tions of the transit of Venus across the sun, taken near 
Kingston, Jamaica, December 6, 1882, by Dr. J. B. Pearson. 
In this paper the author described observations taken by him- 
self of the late transit of Venus, He unfortunately missed 
seeing the first external contact, and only first saw Venus when 
she had intruded about one-third of her sphere on the sun’s disc. 
On the internal contact he noticed no kind of black drop, or 
sympathetic attraction or assimilation between the limb of the 
planet and that of the sun. It seemed to him that when the 
planet was actually projected on the sun’s disc, about 20” before 
the time he assigned for actual contact, the black surface of the 
planet adjoining the atmosphere seemed to begin to be picked 
out with little white dots commencing very probably from either 
side. 
He could not say that he actually saw two horns of light | 
gradually advancing until their poiuts touched, but rather that 
the segment of the planet nearest the cun’s limb, and still ob- 
scure, began to be speckled with white dots which in not more 
than twenty seconds, or twenty-five at the outside, developed 
into a white line. He saw 1othing like an atmosphere around 
Venus, though he looked carefully for it; it was possible that 
his telescope, considerably smaller than what might be called the 
authorised size, was not large enough to show it. 
BERLIN 
Physiological Society, January 26.—Prof. du Bois-Rey- 
mond in the chair.—Prof. Fritsch, who, in his study of the tor- ~ 
pedo at the zoological stations of Naples and Villafranca, has 
discovered, in addition to the facts already published, a series of 
new facts in reference to the development of this electric fish, 
combined these facts with those already discovered by previous 
investigators, and thus produced a general sketch of the develop- 
ment of this remarkable animal before the Society, illustrated by 
numerous preparations, The torpedo exhibits so many different 
forms in its ontological development that already de Sanctis dis- 
tinguished a squaliform stage, a raiform stage, and a torpediform 
stage; and in fact the different stages, as the lecturer demonstrated 
in his series of preparations, first resemble shark-embryos, after- 
wards pass over into the form of rays, and finally change into that 
of torpedoes by the development of the electric organ. The first 
embryonic beginnings of the electric organ have the greatest 
resemblance to embryonic muscular fibres. Upon longitudinal 
section, there are to be seen in the interior of sheaths consisting of 
connective-tissue-cells very distinct longitudinal fibrous striz, 
with traces of transverse striation and many oval nuclei. 
In a later stage, on making a longitudinal section, the longi- 
tudinal fibration and transverse stric are seen to have entirely 
disappeared ; the nuclei have become much more numerous 
and circular, and in the interspaces the disc-like elements of 
the pillars that are to be developed are already to be seen as 
transverse striz. The whole represents, in a sheath of connec- 
tive-tissue, a granular mass of protoplasm with numerous nuclei. 
On making a transverse section, we see in the first stage, in 
which the organ resembles embryonic muscular-tissue, the cut 
ends of the longitudinal fibres as circular contours in an homoge- 
neous connective-tissue. When the electric organ is further 
developed, there is seen, on making a transverse section, a 
polygonal net of connective-tissue, in whose meshes the :ound 
pillars lie, being separated from the walls by cellular masses. 
Hence Prof. Fritsch believes that the histological development 
of the electrical organ is analogous to the transformation of 
normal muscle in myomata, and that it would not be incor- 
rect to call the electric organ anormal myoma. The phylo- 
genetical development of the torpedo has already been described 
in the account of its ontogenetical development. The electric organ 
is developed from muscle, and indeed from the outer gill-muscles of 
the fifth gill-arch. The gill-arch muscle, which develops in rays 
and sharks into the extraordinarily powerful lower-jaw muscle, is 
wanting in the torpedo, and in its place we find the electrical 
organ, which is, comparatively speaking, a more serviceable 
weapon of offence and defence to the small animal than the 
lower-jaw muscle of the related predatory-fishes. The lecture was 
illustrated by a great number of microscopic and macroscopic 
preparations. 
Physical Society, February 2.—Prof. v. Helmholtz in the 
chair.—Dr. Hertz described a series of peculiar light-phenomena 
which he had observed in the case of electric discharges. When, 
in a moderately rarefied space (pressure about 20 to 30 mm. of 
mercury), the electric discharge takes place between electrodes, 
one of which is fixed in a tube that is closed at one end and 
drawn out to a small opening at the other end, while the second 
electrode is placed laterally near the opening of the tube, the 
spark of discharge springs from the opening, laterally, to the 
second electrode; at the same time, however, one sees a ray of 
yellow-brown light break forth from the tube, reaching out a few 
centimetres in the prolongation of it. With stronger or with 
weaker pressure, the ray is shorter and less luminous ; and if a 
Leyden jar be inserted, the ray is also shorter, but it is more 
luminous. The form of this ray (which broadens at the end) 
is very varied; and if it impinges on the wall of the vessel 
inclosing the rarefied space, it produces whirling there. - The 
colour of the ray is different according to the gas: yellow with 
air and oxygen, blue with hydrogen, &c., and spectrum analysis 
hows that it is the respective gases that glow. If a small 
