388 

NATURE 
[June 3, 1915 

statue of Roger Bacon; and cof the completion of the 
carving in the upper corridor, under the bequest of 
the late Rev. H. T. Morgan. 
The report of the Professor of Pathology records 
the fact that from an early date in August the de- 
partment and the whole of its staff were engaged in 
services connected with the war. About 6000 inocula- 
tions were performed, and a quantity of vaccine was 
sent to Belgium. The Professor of Physiology in- 
cludes in his report a tribute to the services rendered 
by the late Dr. G. J. Burch, F.R.S., and an account 
of the arrangements for the memorial to the late 
Prof. Francis Gotch, F.R.S. Most of the depart- 
mental reports, including that of the Curator of the 
Pitt-Rivers Museum, contain long lists of donations 
to the respective collections, and full records of the 
research work which, in spite of all obstacles, has 
been carried on in the various laboratories and work- 
rooms of the Museum. 
The new building for engineering science was 
finished at Christmas. The new chemical laboratory 
is still in course of erection, but the professor hopes 
that it will be ready for occupation by next October. 

_ Science announces that the Michigan Legislature 
has granted 70,0001. for the erection of a new univer- 
sity library building for the University of Michigan. 
Tue fiftieth anniversary celebration of the Worcester 
Polytechnic Institute, Worcester, Massachusetts, is to 
be held on June 6-10. President Wilson, who gave 
the opening address on a similar occasion twenty-five 
years ago, hopes, if the pressure of public business 
makes it possible, to attend the meetings on June 9. 
General G. W. Goethals has also accepted an invita- 
tion to be present. On June 10, honours are to be 
conferred and various bronze tablets unveiled. 
A FREE scholarship of the value of 30l., open to all- 
comers, and tenable at the Northampton Polytechnic 
Institute (London), is being offered to students. In 
view of the opportunities for advancement which the 
calling and craft of optics now offer on account of 
the shutting off cf alien supplies due to the war, the 
“Aitchison Memorial Scholarship,” which has for its 
special object the encouragement of recruits for the 
optical industry, should prove very attractive to intelli- 
gent youths. The subjects of examination include 
English, mathematics, and elementary physics. The 
conditions of the scholarship have been laid down by 
a committee which includes Dr. R. Mullineux 
Walmsley, Prof. Silvanus P. Thompson, and Dr. 
J. W. Ettles. Full particulars can be had of the hon. 
secretary and treasurer, Mr. Henry F. Purser, 35 
Charles Street, Hatton Garden, London, E.C. 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Royal Society, May 20.—Sir William Crookes, presi- 
dent, in the chair.—H. Moore: The corpuscular radia- 
tion liberated in vapours by homogeneous X-radiation, 
—H. Richardson: The absorption in lead of y rays 
emitted by radium B and radium C. (1) The absorp- 
tion curves in lead of the radiations emitted by 
radium B and radium C have been determined and 
analysed. (2) In addition to the penetrating type of 
radiation for which 4=o0-5 (cm.-1) in lead, radium C 
has been found to emit soft types for which »=46, 
=60, and w~=1-5, and which are practically absorbed 
by 1-5 cm. of lead. (3) The analysis of the radium B 
absorption curve shows that in addition to the radia- 
tion ~=40 in aluminium, the rays emitted consist of 
three types for which n=46; “»=6-0, and w=1-5 for 
lead. The close similarity of this latter radiation with 
NO. 2379, VOL. 95] 


that of the soft portion emitted by radium C, already 
observed by Rutherford and Andrade, has been estab- 
lished. (4) The absorption of the radiations in 
different elements has been examined and the bearing 
of the results discussed. No evidence of anomalous 
absorption has been found in the case of the pene- 
trating radiations.—T. R. Merton: The application of 
interference methods to the study of the origin of 
certain spectrum lines. | By measuring the limiting 
orders at which interference can be detected for different 
radiations, certain deductions may be made as to the 
mass of the luminous particles and the temperature of 
the source. If the only circumstance which could 
possibly influence the width of spectrum lines at low 
pressures were the Doppler effect due to the motion of 
the luminous particles in the line of sight, the relative 
masses of particles emitting radiations from the same 
source of light might be calculated. As, however, 
there is reason to doubt the validity of this assumption 
under certain conditions, the conclusions which may be 
drawn with certainty from measurements of this kind 
are an inferior limit for the mass of the luminous 
particles if the temperature of the source is known, 
or a superior limit to the temperature if the mass of 
the luminous particles is assumed. It is shown in the 
paper that the flame lines of calcium, strontium, and 
barium are probably due to molecules, whilst the H 
and K lines of calcium are to be attributed to calcium 
atoms. As the flame lines are members of series, it 
must be recognised that radiations from molecules 
may give rise to line series as well as band spectra. 
Lines of the two spectra of argon have been investi- 
gated. The width of the lines of the red spectrum 
would appear to be accounted for by the Doppler 
effect. The lines of the blue spectrum are very broad 
in comparison with those of the red spectrum, and a 
satisfactory explanation of this has not been found. 
Spectrum lines of the ‘‘arc”’ type are broadened when 
condensed discharges are used as the method of excita- 
tion, but the difference in width of the lines in the 
blue and red spectra of argon is of another order 
of magnitude. The band spectrum associated with 
helium has been found to be enhanced when the gas 
is cooled to the temperature of liquid air, which might 
justify the suspicion that more than one atom was 
concerned in its production, but a comparison of the 
widths of the lines in the band spectrum with the 
ordinary helium lines makes it extremely probable that 
the band spectrum is due to atomic helium. 
Physical Society, May 14.--Dr. A. Russell, vice- 
president, in the chair.—E. H. Rayner: Precision 
resistance measurements with simple apparatus. The 
paper describes methods by which the comparison of 
resistances can be made to an accuracy of 1 in 10,000 
or higher by using simple apparatus usually available 
in electrical laboratories, or which can be easily con- 
structed with little skilled assistance. The comparison 
of nominally equal resistances of 1 ohm and upwards 
by the usual method of shunting one side of a nearly 
balanced quadrilateral by a high resistance is men- 
tioned, and variations on this when only part of one 
resistance is shunted are often useful. The great 
advantages of having resistances capable of carrying 
comparatively large currents are illustrated, especially 
for measuring changes of resistance of commercial 
apparatus under working conditions. The determina- . 
tion of errors in a volt box for use with a potentio- 
meter is described at some length. This is of especial 
importance in precision photometry. If a sufficient 
continuous-current voltage is not available for testing 
such apparatus as high-potential dividers, it is shown 
that using sufficient continuous current to secure 
sensitivity the heating may be supplied by superposed 
alternating current. Resistances in common use are 
