April 7, 1904] 
NATURE 
55% 
mainly directed to the higher instruction needed to train 
men for engineering and other employments in Government 
service or in mines, mills, &c. Valuable work has been 
done in colleges of engineering and science, and their de- 
velopment is of great importance. But, with a view to the 
development of Indian industries by native capital for the 
supply of Indian markets, special technical training must 
be afforded, resting on the basis of a simple and practical 
general education acquired in the ordinary schools. In 
order to provide qualified men for improving Indian in- 
‘dustries Government intends to offer scholarships to enable 
selected students to obtain technical instruction in Europe 
and America, and it invites the advice and aid of the com- 
mercial community in selecting the industries to be studied, 
in choosing the students, and in turning the knowledge 
acquired to practical account. 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Zoological Society, March 15.—Dr. Henry Woodward, 
F.R.S., vice-president, in the chair.—Mr. R. Lydekker 
read a paper on the skull and markings of the quagga, in 
which he directed attention to vestiges of the face-gland 
of Hipparion in the skull, and expressed his belief that 
certain alleged differences in the colour and markings of 
various specimens of the quagga were due to feeding or to 
the manner in which such markings came out in photo- 
graphs. Mr. Lydeikker also read a paper on the wild ass 
of Mongolia, of which an example was in possession of the 
president at Woburn Abbey, and expressed his opinion that 
it was the true Equus hemionus of Palias, and distinct from 
‘the ass of Tibet and Ladak. The latter he proposed should 
bear the name Equus hemionus kiang.—Mr. R. I. Pocock 
described a new species of spot-nosed monkey, of the genus 
Cercopithecus, from Benin, West Africa.—Mr. F. E. 
Beddard, F.R.S., read the first of a series of papers entitled 
** Contributions to the Anatomy of the Lacertilia.”’ 
with the venous system of Iguana tuberculata, Tiliqua 
scincoides, and Varanus griseus.—Mr. Percy I. Lathy con- 
tributed a paper dealing with a collection of butterflies from 
Dominica, West Indies, of which three were described as 
new and thirteen had hitherto not been recorded from the 
island. 
Faraday Society, March 21.—Dr. O. J. Steinhart in 
the chair.—On the electrolytic analysis of gold: F. M. 
Perkin and W. C. Prebble. The object of the researches 
described was to arrive at an electrolytic method of estim- 
ating gold which should be perfectly accurate and yet far 
more rapid than the ordinary double cyanide method. Solu- 
tions of sodium thiosulphate, of cyanide, of sodium sulphide, 
of potassium thiocyanate and of ammonium thiocyanate were 
all tried and the results compared. The first named was use- 
less ; of the others—which are all accurate—the thiocyanates 
gave the best results, and the ammonium salt was better 
than the potassium. With currents of 0-2 amp. per sq. 
dem. the deposition of 0-05-0 08 gm. of gold was complete 
in 5 or 6 hours. With a current of 0 4-0-5 amp. 13 to 2 
heurs. sufficed.—Thin-film electrolysis, and a_ proposed 
application to printing: C. R. Darling. While investi- 
gating a process for letterpress printing by electrolysis 
without the use of ink—an extension of “Bain’s well known 
telegraphic printing—the author found that the final results 
of electrolysis, when the electrolyte forms only a thin film, 
often differ materially from those observed in an ordinary 
cell. In these experiments a carbon or metal plate (it was 
immaterial which) formed the anode; on this was placed 
41 impression pad, consisting of some sheets of moist 
blotting-paper, upon this was the trial sheet, carrying the 
electrolyte film, and on this the kathode type or coin. The 
first experiments were made with saline solutions; silver 
nitrate gave a clear, permanent black image of the type, but | 
th» paper, of course, darkens on exposure; copper sulphate 
and nitrate yielded images that faded after a time; the 
same unexpected result occurred with lead, mercury salts and 
bismuth. The best images were obtained with manganese 
salts. 
Physical Society, March 25.—Dr. R. T. Glazebrook, 
F.R.S., president, in the chair.—Note on the measurement 
of small inductances and capacities and on a standard of 
NO. 1797, VOL. 69] 
small inductance: Prof. Fleming. The author referred to 
a paper read before the society last year by Mr. W. C. 
Clinton and himself, in which a motor-driven commutator 
was employed to measure small inductances. It had since 
been found that very good results could be obtained in the 
measurement of small inductances by Prof. Anderson’s 
method by using a telephone in place of a galvanometer and 
a buzzer in the battery circuit. The author had found that 
for long solenoids, at least 50 diameters long, the inductance 
could be calculated with an accuracy of about 1 per cent. 
by the rule :—Inductance in cm.=(length of wire in one 
unit length of solenoid) x (total length of wire in the whole 
solenoid in cm.).—A hot-wire ammeter for measuring very 
small alternating currents: Prof. Fleming. The author 
said that in alternating current work, particularly in taking 
the power factor of small transformers and of short lengths 
of cables, the need had been felt for an ammeter not in- 
volving the use of iron capable of measuring currents as 
small as oor or less of an ampere. He exhibited an 
ammeter capable of being made to read currents as small 
as 0-002 with fair accuracy. The arrangement was as 
follows :—Two very fine platinoid or constantin wires, about 
1 metre long and 005 or even 0-02 mm. diameter, are sup- 
ported on a wooden rod with arrangements for adjusting 
their tensions. These wires are 5 mm. apart, and are held 
down at the centre by delicate spiral springs. The two 
wires are embraced at the middle by a small loop of paper 
carrying a very small plane mirror. These wires are 
enclosed in a box, the lid of which carries a lens. By this 
means the light of a straight carbon filament of a glow- 
lamp, or of a slit illuminated by an arc lamp: reflected by 
this small mirror can be focused on a screen of ground 
glass. If a current is passed through one of these wires 
it sags down slightly, and the square root of the displace- 
ment of the image on the screen is almost exactly pro- 
portional to the current passing.—Dr. W. Watson exhibited 
| and described a form of ammeter for small alternating 
It dealt | currents. 
The current to be measured flows through a piece 
of iron wire bent into the form of a right angle. This is 
linked with a similarly shaped piece of nickel wire forming 
part of a galvanometer circuit. The thermo-E.M.F. at the 
| junction, produced by the heating effect of the current, sends 
a current through the galvanometer which can be measured 
in the usual way. The current to be measured is practically 
proportional to the deflection of the galvanometer.—Energy 
of secondary Rontgen radiation: C. G. Barkla. To 
measure the intensity of radiation electroscopes were placed 
in a primary beam of Réntgen rays and in a secondary 
beam proceeding from air in a direction perpendicular to 
that of propagation of the primary rays. By comparison 
of the two rates of leak when no absorbing plates were used 
and when similar aluminium plates were placed before each 
electroscope, it was found that the absorbability of the 
secondary rays differed from that of the primary by less 
than 5 per cent. of its value. It was, however, found that 
a secondary beam of the same intensity as the primary 
would produce a slightly different number of ions in a given 
volume of air, consequently the radiations differ slightly in 
character. The difference in what may be called the 
“ jonising powers ’’ was evidently greater when the primary 
beam consisted of more penetrating rays. The fraction of 
energy lost in secondary radiation was very nearly, if not 
entirely, independent of the character of the primary radi- 
ation. The law which the author had previously found to 
govern the intensity of radiation from gases was found to 
be equally applicable to those light solids which are the 
source of a radiation differing little in character from the 
primary, t.c. the energy of secondary radiation ffom these 
substances situated in a beam of definite intensity is pro- 
portional to the quantity of matter through which the 
primary beam passes. 
Paris. 
Academy of Sciences, March 28.—M. Mascart in the 
chair.—On the physical constants of some fluorides of 
phosphorus: Henri Moissan. Phosphorus trifluoride, 
pentafluoride, and oxyfluoride were liquefied after careful 
purification, and their melting points and boiling points 
determined by means of an iron-constant in thermo-couple. 
—On the production of quartziferous rocks in the course of 
the eruption of Mont Pelée: A. Lacroix. From an extended 
| series of observations on Mont Pelée, the conclusion is drawn 
