Oct. 29, 1885 | 
NATURE 
635 
rately turned and adjusted, and the dimensions are all known 
within one five-thousandth. For the measurement of small 
currents there are two circles, about 1°5 metres diameter, each 
having two conductors, and comprising altogether 72 turns of 
No, 12 copper wire. 
THE indications of such an instrument of course depend upon 
the value of the horizontal intensity of the earth's magnetism, 
and without some means of determining this quantity in the 
place where the instrument stands, and at the time when a 
measurement is being made, no great accuracy is attainable. 
For making this determination, a coil a metre in diameter, con- 
sisting of foo turns of No. 18 wire, is suspended, so that its 
centre coincides with the centre of the instrument by means of 
a single phosphor-bronze wire, which is itself attached to a 
torsion-head reading to ten seconds of arc. By the aid of this 
coil, observations may be taken at any moment for the deter- 
mination of H by the method proposed by Sir William Thom- 
son. The instrument is mounted ina copper building, from the 
construction of which all iron has been rigidly excluded. Several 
conducting;wires connect the building with the dynamo and other 
rooms of the physical laboratory, 550 feet distant, and switches 
in the building serve to send the currents through the several 
coils of the galvanometer singly, in series, or in multiple arc, 
direct or reversed. By this nveans currents from 1 milliampere 
to 250 amperes can be accurately measured. 
THE last number (Heft 33) of the AZitthei/ungen der Deutschen 
Gesellschaft fiir Natur und Vilkerkunde Ostasiens contains a 
paper by Herr Hiitterott on the Japanese sword, with numerous 
illustrations of the various forms. It describes the manner in 
which it is forged, how it reaches the extraordinary degree of 
excellence for which it is celebrated, in short the technique of 
the making of a Japanese sword in the feudal days. Herr 
Mayet concludes his account of a visit to Corea, the first part 
of which we have already noticed. Dr. Naumann, the 
director of the Geological Survey of Japan, and Japanese 
representative at the late Geological Congress at Berlin, com- 
municated an extract from a report of his on the geological 
structure of the Japanese islands. 
ONE-TENTH of the ‘‘ Studentenschaft ” at the Zurich University 
is now female. Twenty-nine young ladies study medicine, four- 
teen philosophy, and two politicil economy. Of the forty-five 
female students, fifteen are Swiss, and ten Russian. 
THE after-sunglow has again at times been visible in Stock- 
holm, from the middle of August to the middle of September, 
being distinct from the ordinary evening aurora. 
A FURTHER telegram has just been received by the Russian 
Minister of War from Col. Prjevalsky, dated Osh, September 30 
—that is, the r2th imst., new style. Only the concluding 
passage has as yet been published by the Russian papers :— 
** August 14 (new style, August 26), Oasis of Tchira.—I have 
explored the Keria Mountains. We are now proceeding wid 
Khoten and Aksu, and we shall arrive in Semiretchia towards 
the end of October. All is well.” 
THE spheroidal state of liquids has recently been made an 
object of study by Signor Luvini (27 Maove Cimento). A curious 
phenomenon was noticed when air was blown into the drop (to 
test the view that liquids in that state do not boil because they 
have lost their dissolved air), There arose bubbles often larger 
than the mass of liquid, and very persistent ; they shared the 
movements of the drop and sometimes moved independently. 
Such bubbles were had in pure water, soapy water, alcohol, and 
ether, and would probably arise in all liquids. Sometimes they 
appeared only after the tube was withdrawn. Signor Luvini 
infers that liquids in the spheroidal state do not lose their dis- 
solved air, or lose it very little. The author made arrangements 
for observing the spheroidal state under different air pressures, 
and he came to the conclusion that the temperature of each 
liquid in that state, under a given pressure, is very nearly equal 
to the least boiling temperature of the liquid under the same 
pressure. 
WE have just received from the secretary, Mr. Charles Bailey, 
F.L.S., of Manchester, the reports of the Botanical Exchange 
Club for the years 1883 and 1884. For 1883 Mr. G. Nicholson 
acted as distributor, and 3735 specimens were received and 
divided out again among-t the members. In 1884 Mr. Arthur 
Bennett undertook the labour of distribution, and the number 
of specimens placed in circulation was 4371. The two reports 
contain a series of annotations by the distributors upon the more 
interesting plants which passed through their hands. For a 
considerable number of species new counties are registered. 
The most interesting additions to the British flora, of which 
they make mention, are a Scwéel/aria, intermediate between 
minor and galericulata, perhaps a hybrid, found by Mr. Nichol- 
son in a place one would have thought likely to be thoroughly 
explored long ago—-the shores of Virginia Water ; Potamogeton 
fiuitans, a pond-weed very difficult to recognise, found by Mr. 
A. Fryer in Huntingdonshire ; and Carex salina, a boreal spe- 
cies known already in Scandinavia, Iceland, the Faroes, Nova 
Zembla, and North America, which has lately been discovered 
by Mr. Grant in Caithness. The Rubi of Britain want carefully 
comparing with those of the Continent, and Mr. Arthur Bennett 
has done well to send the Club specimens to be verified by Dr. 
Foche, of Bremen, whose synopsis of the German Rubi has 
been taken lately by Hyman as a basis for his enumeration of 
the European forms in his most useful geographical conspectus of 
the European flora. 
A curious calculation has been recently made by Signor 
Bartoli regarding the mean density of a body which should con- 
tain all the known elements in a solid state, either uncombined, 
or, if partly combined, each retaining the density belonging to 
it in the solid state. The author makes three suppositions—(1) 
the masses of all the substances equal ; (2) masses such that the 
corresponding volumes are equal ; (3) masses in ratio of the 
atomic weights. The corresponding mean densities he arrives 
at are 2°698, 7'027, and 5°776, and it is pointed out that the 
last value comes very near that got by Cavendish for the mean 
density of the earth, viz. 5°67 ; possibly an accidental agree- 
ment, yet interesting. 
WE have received from Mr. Francis Day copies of two papers, 
on a subject on which he also read a paper at the Aberdeen 
meeting of the British Association. One is entitled ‘‘ Notes on 
the Breeding of Salmonidz,” being observations on the fish 
cultural experiments being carried on at Howietown, and on 
experiments by the author himself at Cheltenham. The second, 
from the 7yansactions of the Linnean Society, is on the breeding 
of salmon from parents which have never visited the sea. This 
also describes the results of experiments at Howietown. 
WE have received the report of the Council of the Leicester 
Literary and Philosophical Society for the past year. Various 
important additions have been made to the town museum ; the 
work on the flora of Leicestershire, undertaken and edited by a 
botanical sub-committee, is now in the press, and will shortly be 
published ; the resolution, adopted at the last general meeting 
of the society, for the promotion of science classes in the town 
has, owing to various circumstances, only beea partially carried 
out. Two experimental classes, one for pure mathematics, the 
other for physiology, have been commenced, and have been 
attended with fair results. The reports of the various sections 
show a considerable amount of work done during the year. 
