- JULY 31, 1902] 
apparently to the iron molecules being momentarily released 
from constraint. A sudden variation in the magnetisation of the 
iron results, and this induces a current in the outer copper wind- 
ing connected to the telephone. The author finds that the 
telephone reproduces very accurately the transmitted signals, and 
that the receiver is more sensitive than the coherer and more 
suitable for use with a syntonic system of wireless telegraphy. 
Experiments with the receiver have been carried out between 
St. Catherine’s Point and North Haven, the distance between 
these points being 152 miles; the length of the electric waves 
used was 200 metres. 
‘© 4 Note on the Effect of Daylight upon the Propagation of 
Electromagnetic Impulses over Long distances.” By G. 
Marconi, M.I.E.E. Communicated by Dr. J. A. Fleming, 
F.R.S. 
During the experiments carried on between Poldhu, Cornwall, 
and the U.S. s.s, Philadelphia it was observed that the signals 
transmitted at night had a greater carrying power than those 
transmitted by day. The transmitting conductor consisted of 
fifty bare copper wires suspended from a wire stretching between 
two poles 48 metres high. On board ship the receiving con- 
ductor was suspended from the mast and was composed of four 
wires the topsof which were 60 metres above the sea level. Signals 
were sent from Poldhu at stated intervals from 12 to I am., 
from 6 to 7 a.m., from 12 tol p.m. and from 6to7 p.m. Until 
the Philadelphia was 500 miles from Poldhu no differences were 
observed ; at distances of more than 700 miles signals transmitted 
during the day failed entirely, whereas those sent at night remained 
quite strong up to 1551 miles and were decipherable up to 2099 
miles. Daylight at Poldhu was rapidly increasing from 6 to 
7 a.m., and it was observed that on the Phz/ade/phia the signals 
which were quite clear at 6a.m. had almost disappeared by 
7.a.m. Confirmatory tests were carried out between Poldhu and 
North Haven, and it was found that receiving wires 12°I metres 
high could be used at night, but that, other things being equal, 
the height had to be increased to 18°5 metres for the daylight 
signals to be equally clear. The author suggests that the effect 
may be due to the diselectrification of the transmitting elevated 
conductor by daylight, the electrical oscillations being thereby 
prevented from acquiring so great an amplitude as they attain 
during darkness. That the effect has not been previously 
noticed may be due to the extra high potential to which the 
aérial wires at Poldhu were charged for this long-distance work. 
This potential was sufficient to cause sparking between the tops 
of the wires and an earthed conductor 30 cm. distant. 
EDINBURGH. 
Royal Society, June 16.—The Hon. Lord M’Laren in the 
chair.—Prof. C. G. Knott read a paper on the change of resist- 
ance of nickel due to magnetisation at various temperatures. 
The apparatus used had been constructed twelve years ago in 
Japan, but other work had prevented anything like a thorough 
investigation being made with it. Two exactly equal pieces of 
nickel wire were coiled so as to form anchor-ring cores to 
magnetising coils of copper wire coiled round them. Round 
each nickel wire were coiled two distinct coils with exactly the 
same number of turns. Thus by joining up the coils in different 
ways the experimenter was able to subject the enclosed nickel 
to a strong magnetic field or to no field, without in any way 
altering the strength of current circulating in the coils. The 
nickel coils were balanced on a Wheatstone bridge. The 
magnetising current was passed round the pairs of coils on the 
nickel cores, so as to magnetise the one nickel but not the 
other. In this way the heating effect was practically the same 
in both coils and the change of resistance due to heating very 
nearly compensated. The coils were heated up to various 
temperatures in an air bath and the resistance change was 
measured by deflection after a balance was nearly adjusted. 
The galvanometer was gauged by means of the deflection pro- 
duced when a definite change of resistance was made in one 
arm of the bridge. The first series of experiments indicated 
that there was a decrease in the proportional change at higher 
temperatures ; but this showed that the total amount of change 
estimated in ohms for any given wire was very nearly the same 
at all temperatures between the limits of 10° and 170° C. The 
bearing of this result upon Prof. J. J. Thomson’s theory of cor- 
puscles was pointed out ; but further results were held over for 
another communication,—Prof. Knott also gave an account of 
the last piece of quaternion work which Prof. Tait had jotted 
down on July 2, 1901, just two days before his death. The 
NO. 1709, VOL. 66] 
NATURE 
335 
notes bore upon the properties of the linear vector function 
and were a following up of previous work published in the 
Proceedings.—Dr. Hugh Marshall described the results obtained 
by him in the first part of an investigation of the thallic sul- 
phates and double sulphates. From these it would appear that 
it is largely a matter of solubility whether normal or basic salts 
are obtained, rather than a matter of sulphuric acid concentra- 
tion. Thus, potassium thallic sulphate, KTI(SO,).,4H,O, when 
treated with dilute sulphuric acid gives a sparingly soluble basic 
salt} K,TIOH(SO,),; the latter dissolves easily in dilute nitric 
acid and this solution gives crystals of the first-mentioned normal 
salt. No thallic alums could be obtained. 
July 7.—Sir William Turner in the chair. —An obituary notice 
of Lieut.-Colonel J. H. B. Hallen, C.I.E., F.R.C.S.E., was 
communicated by Principal W. Owen Williams.—Mr. J. G. 
Goodchild contributed a paper on Scottish mineralogy, based 
upon a study of the specimens under his charge in the Edinburgh 
Museum of Science and Art. It dealt chiefly with the develop- 
mental history of albite studied in relation to crystal genesis in 
general, The paper also dealt with the crystallography of 
Scottish cerussite, analcine, forsterite and some others. Draw- 
ings of a large number of crystals were exhibited.—Mr. James N. 
Miller demonstrated the mode of applying his mechanical tri- 
sector to the quinquesection of an angle. It was an ingenious 
extension of the properties of the trisector.—In a paper on ex- 
perimental observations on leucolysis, by Drs. A. Goodal and 
E. Ewart, the following conclusions were arrived at :—(1) Necro- 
biotic changes occur in the circulatory leucocytes in health ; (2) 
these changes are much more evident in conditions of impaired 
nutrition and toxzmia, notably in cancerous cachexia ; (3) in 
toxic conditions usually associated with leucocytosis the extent 
of the necrobiotic changes in the white cells varies in inverse 
ratio to the number of leucocytes in the circulating blood ; (4) 
these necrobiotic changes can be rapidly induced ‘‘in vitro” by 
the action of certain organisms or other products ; (5) the rapidity 
and extent of the changes depend on the kind of organisms, the 
virulence of the culture and the number of organisms employed. 
—In a paper on cross-magnetisation in iron, Mr, James Russell 
described a large number of experiments showing how the in- 
duction, either longitudinal or circular, was affected by cross 
fields and how the effects of these cross fields were themselves 
reacted upon. As one among many results, consider the case 
of a steady longitudinal field with a cyclically changing circular 
field superposed. The induction due to the longitudinal field 
went through a corresponding cycle with its maximum points 
occurring at the instants of greatest change in the cyclic circular 
field. The cyclic change in the longitudinal field was very 
similar in form to the change accompanying twisting.—In a 
note on a suggested improved method of measuring deep-sea 
temperatures, Prof. Knott called attention to the unsatisfactory 
character of the methods at present in use, and advocated the 
use of the platinum thermometer, with which the temperature 
must be taken z sz¢z. Various obvious difficulties in the way 
of applying the platinum thermometer to deep-sea work were 
considered, also the manner of measuring the depth at the instant 
of taking the reading. For experiments down to moderate 
depths there was no special difficulty in using these electric 
resistance thermometers, and by such rapidly acting apparatus 
important problems connected with the penetration of solar 
radiation through surface waters could be readily solved. 
Paris. 
Academy of Sciences, July 24.—M. Bouquet de la Grye 
in the chair.—On electrolytic actions developed by batteries 
consisting of two liquids, one being an acid, the other an alkali, 
by M. Berthelot.—On the existence in the albumin of birds’ 
eggs of a fibrogen substance capable of being transformed, 7 
vitro, into pseudo-organised membranes, by M. Armand Gautier. 
Fresh white of egg, after filtration through paper, was diluted 
with water and treated with a current of an indifferent gas, such 
as nitrogen or carbon dioxide. A substance is precipitated in 
the form of white transparent membranes, possessing a rudi- 
mentary organisation, and approximating in composition to the 
fibrin of human blood and to myosin, but differing considerably 
from egg-albumin.—On the glycuronic acid in the blood of the 
dog, by MM. Lépine and Boulud.—Report on a memoir of M. 
Torres concerning a scheme for a steerable balloon presented to 
the Academy on May 26. The committee regards the work of 
M. Torres as constituting a very interesting contribution to the 
theory of steerable balloons, and considers it desirable that 
