* 
April 20, 1882] 2 
NATURE 
wt 
595 
Chemical Society, April 6.—Dr. Gilbert, president, in the 
chair.—The following papers were read:—On the action of 
acetyl chloride on fumaric acid, by W. H. Perkin. The author 
criticises the statements of Auschiitz, and considers that the views 
of that chemist as to the above reaction are unsatisfactory. 
Probably the acetyl chloride removes a molecule of water from 
the fumaric acid yielding maleic anhydride.—Some arguments 
in favour of the prism formula of benzene, by U. K. Dutt.— 
On a convenient apparatus for the liquefaction of ammonia, by 
J. Emerson Reynolds. This essentially consists of a stout iron 
U-tube, into one lez of which is cemented a stout glass tube, 
containing dry ammonia gas; the other leg of the U, which is 
closed by an iron cap, contains some strong solution of ammonia. 
The intermediate space is filled with mercury. On heating the 
solution, pressure is produced, sufficient to liquefy the gas.—On 
the transformation of urea into cyanamide, by H. J. H. Fenton. 
On gently heating urea with metallic sodium, a violent reaction 
ensues ; hydregen is evolved, and a body, having the compo- 
sition and all the properties of cyanamide, is formed.—On the 
action of haloid acids upon bydrocyanic acid, by L. Claisen and 
F. E. Matthews. A crystalline substance, having the formula 
211CN+3HCI, is obtained. By the action of alcohol on this 
body, the hydrochloride of the base, HCNHNHs, was pre- 
pared, 
Royal Horticultural Society, April 11.—Dr. M. T. Masters 
in the chair.—/ododendrons : Mr. Mangles and Hon. and Rev. 
_ Mr. Boscawen exhibited species, seedlings, and hybrids of which 
the following were specially worthy of note :—/. Forstertanum— 
hetween A. Ld;eworthii (male) and 2. Veitchianwm (female), 
raised by M, Otto Forster, of Lehenhof, Austria. It is a beautiful 
combination of both parent forms, being very Jarge and fragrant. 
It appears to be quite barren. Hybrid between &. campylo- 
carpum (yellow, male) and a crimson hybrid (female). The 
flowers are pendulous. The yellow tint of the male has nearly 
sone, but the characters of the flowers are retained. It is pink 
when first opening, but almost white finally. This hybrid has 
good pollen, and bears seed.—Hybrid between 2. Zomsont 
and &. Fortune’. It is peculiar in having far more flowers in the 
truss than either parent. It is apparently fertile, and has an 
abundance of good pollen.—Hybrid between 2. axgentewm and 
R, ponticum. The flower is very inferior to that of the male, 
which bears large, well-shaped white flowers, being small, 
tubular, and pink, with aborted anthers. The colour of ‘ponti- 
cum being prepotent.—Ayacinth blossoming underground: Mr. 
A. H. Smee, of Wellington, sent a specimen which, in conse- 
quence of being under a stone, had blossomed six inches below 
the surface. The leaves were white, but the flowers a deep 
purple.—lants exhibited: Teleopea speciosissima. Mr. Green, 
gardener to Sir G. Macleay, exhibited a splendid truss of scarlet 
flowers and bracts of this proteaceous genus from Sydney, where 
it is a common shrub, but produces much less fine blossoms there 
than the specimen exhibited. It was first figured in the Bos. 
Mag. in 1808. He also exhibited a fine specimen of the 
monkey orchis, from Italy. . 
EDINBURGH 
Royal Society, April 3.—Prof. Balfour, vice-president, in 
the chair.—Sir William Thomson read a paper on the condi- 
tions of stable equilibrium of a rotating mass of gravitating 
liquid. Laplace had proved that a given moment of momentum 
ina given mass of fluid of oblate spheroidal form, such as had been 
shown to be a form of equilibrium by Newton and Maclausin, 
required for equilibrium a unique value of the excentricity. 
Jacobi had extended the theorem to the case of an ellipsoid rotating 
round the shortest of its three unequal axes. By considering the 
Jacobian ellipsoid which differed infinitely little froma spheroid of 
revolution, Sir William found a certain value for the moment of 
momentum such that the equilibrium of the spheroid would be 
stable if, and only if, its moment of momentum were not greater 
than this critical value. The cenditions under which a disc- 
shaped ellipsoid would split up into two distinct masses, and the 
limiting values of the excentricities in the Jacobian figure con- 
sistent with stability, were also discussed.—Prof. Vait com- 
municated a note by Prof. C. Michie Smith on atmospheric electri- 
city, which the author had found to be strongly negative on the 
Suez Canal and in Madras, on occasions when other evident 
atmospheric conditions would have led one to expect strong 
positive electrification.—Prof, Chrystal communicated an inter- 
esting paper by Mr. A. Jamieson, on recent tests of Swan’s 
lamp for fall of resistance with increase of electromotive force, 
and ratio of candle-power to work expended. Curves and tables 
of numbers were shown, giving the relations between these quanti= — 
ties for all the forms of incandescent lamps now in use. The 
resistance of the lamps when heated was measured by shunting 
the current through a high resistance galvanometer—Sir W. 
Thomson’s potential galvanometer. The energy expended in keep- 
ing the lamps incandescent was estimated, and the results obtained 
with the incandescent lamps compared with those obtained by 
other investigators with the are light —Dr. A. P. Aitken communi- 
cated the results of preliminary observations made by the Com- 
mittee appointed by the Highland and Agricultural Society to 
investigate the nature and causes of the two sheep diseases, 
“Loupingill” and ‘*Braxy.”” Regarding the former a great variety _ 
of opinion existed as to its cause—inclement weather, bad herding. 
the presence of ergot in the pasture, ticks, &c., being all assigned 
as possible causes. The committee had concluded, however, 
that these were merely aggravations, and that the disease was 
probably due to the presence of an organism located in the 
cerebro-spinal fluid. The investigations into the nature of Braxy 
were just begun; but in the coming autumn the committee hoped 
to continue the inquiry.—Prof. Tait, in the first of three short 
notes, pointed out the origin of the difficulty of measuring 
beknottedness electromagnetically. He traced it to the fact that 
every knot may be Jcoked upon as consisting of separate loops, 
which may be linked or Jaced together. When there is linking 
there is electromagnetic work; when there is lacing, none. 
In the second he showed that the form of Saturn’s shadow on a 
plane as seen from the earth could be calculated by the sane 
process as that employed for the image of a circle produced by 
a thin prism; and also, how to determine from the odserzd 
appearance of the shadow the form of the meridional section of 
the rings supposed to be surfaces of revolution. Finally he 
pointed out the analogy between Action in particle-dynamies and 
Velocity-potential in hydro-kineties 
PARIS 
Academy of Sciences, April 8.—M. Jamin in the chair.— 
The following papers were read :—On the elliptic integral of the 
third species, by M. Hermite.—Note on the principle of a new 
photographic revolver, by M. Janssen. In the old instrument 
the plate is stopped each time an image is taken; in the new, it 
and the screen with slit have each a continuous rotaiory motion. 
The magnitude and relation of these motions determine the 
rapidity of succession of the images and the conditions of their 
formation, The method proved successful with solar granulations. 
Images may be had at intervals of less than 34, second ; thus an 
insect’s flight might be photographed.—Haloid salts of silver and 
potassium, by M. Berthelot.—On the union of free hydrogen 
with ethylene, by the same.—On the specific heat of hyponitric 
acid, by MM. Berthelot and Ogier.—On a thesis of meteorology 
recently maintained before the Paris Faculty of Sciences, by M. 
Faye. In this thesis, on the foehn and the sirocco, M. Hebert 
has recourse to the theory of descending vortical movements, 
and M. Faye regards this as a step in advance. Progress would 
be accelerated (he urges) by giving meteorology a place in the 
Faculties.—On some types of plants recently observed in the 
fossil state, by M. de Saporta. These plants are from the 
Permian of the Oural region, and the Cretaceous of the Fuveau 
valley (Bouches-du-Rhéne).—M. Bert was elected Member in 
Medicine and Surgery, in room of the late M. Bouillaud. 
—Researches on the passage of electricity through rarefied 
air, by M. Edlund. He has proved experimentally that the 
principal obstacle met by the current at the surface of passage 
between the electrodes and the rarefied gas, is due to an electro- 
motive force giving an opposite current; which force, beyond a 
certain limit of rarefaction, continuously increases.—On a class 
of unicursal curves, by M. Darboux.—On hypercycles, by M. 
Laguerre.—On uniform doubly periodic functions, with essential 
singular points, by M. Appell.—On the theory of uniform func- 
tions of a variable, by M. Mittag-Leffler.—General relation 
between any seven points of a conic section; conic of homology ; 
properties common to three homographic figures, by M. Parry.— 
Study of solar apparatus, by M. Crova. This gives results of a 
year’s experiments by a Government Commission at Montpellier 
with a solar mirror and boiler ; (similar experiments have been 
made at Constantine). The maxima of yield generally corre- 
spond to the minima of intensity of radiations. The absolute 
quantity of heat utilised depends essentially on the temperature 
of theair. In our climates it is not possible to reach half the 
utilisation realisable in the most favourable circumstances ; and 
