398 
It appears that cultures of many pathogenic organisms have 
been obtained secently from the excreta of the common house- 
fly, Musca domestica. The réle played by these insects in the 
dissemination of enteric fever in South Africa was referred to, 
and Sir James remarked that one of the collateral advantages 
of our campaign in South Africa might prove to be the opening 
of our eyes to the part played by flies as disease mongers. 
The enormous fertility of the ordinary fly forms one of the 
chief obstacles to its extermination ; it has been calculated that 
one female fly may have 25,000,000 descendants during one 
season. 
MEssrs. COOK, the tourist agents, have put forward a pro- 
posal to run an electric railway to the crater of Vesuvius from 
the Naval Arsenal in Naples to take the place of the 
funicular railway now used. The Faculty of Science in the 
University of Naples has forwarded a strong protest against 
the scheme to the Italian Government, on the grounds that it 
would interfere with the seismic and magnetic observations and 
records which are made at the University. 
THE lecture delivered by Mr. J. Swinburne before the Incor- 
porated Gas Institute, on the electrolysis of gas mains, is a 
valuable and impartial 7ésé of the whole subject. Few will 
disagree with the conclusion that the question is not really 
settled, and that although electrolysis undoubtedly takes place 
it is hardly possible at present to say whether it is serious or not. 
Mr. Swinburne urges the gas and water companies to watch 
carefully ; should serious corrosion be observed some means 
must be found of making those who are responsible pay for the 
damage, though it is to be feared there will be difficulty in 
fixing the responsibility in towns, such as London, where there 
are a number of electric tramways and railways. The lecture is 
reprinted in the last two issues of the Hlectrécéan. 
Ir is proposed to work electrically that part of the New 
York Central Railway which runs through the city, the 
principal motive for the conversion lying in the fact that two 
miles of the track are in a tunnel, The scheme involves the 
electrification of thirty miles of track, at a cost of nearly three 
million pounds, and requires a power station with an output 
of 100,000h.p. As a result of tests with a dynamometer car 
on a portion of the lines, estimates of the cost of working 
with different electrical systems have been prepared. These 
are embodied in a paper read by Mr. D. J. Arnold before the 
American Institution of Electrical Engineers. Local conditions 
have largely determined what system shouldjbe recommended, 
and that which works out cheapest has in consequence not 
been chosen. The one selected comprises a combined alter- 
nating- and direct-current generating station near the outer end 
of the line and a substation at the other end, with batteries in 
both. The alternate-current transmission is at 11,000 volts 
and the direct-current working pressure is 600 volts. The total 
cost with this system is estimated at 23°63 cents per locomotive- 
mile as against 24°18 cents with steam. The economy is little 
enough, and would not be sufficient to justify the conversion 
unless there were other considerations. The Z/ectrician justly 
points out that the scheme, if adopted, can hardly fail to be 
merely the stepping-stone to the complete conversion of the 
whole railway. 
A PAPER has been contributed to ‘the Lombardy Rendzcontz, 
xxxv. 15, by Dr. Edoardo Bonardi, in which the author asserts 
his disbelief in the existence of specific characters in bacteria, and 
considers that a curative serum has no rigorously specific action, 
but that its action in curing infectious diseases consists in its 
strengthening the animal organism against the attacks of disease 
germs, 
FRoM Prof, Garbasso we have received the reprint of a note 
communicated to the 4/¢7 of the Italian Electrotechnical Asso- 
NO, 1712, VOL. 66] 
NATURE 
[AucusT 21, 1902 
ciation on the condition under which two conductors arranged 
in multiple arc are equivalent to a single conductor when self- 
and mutual-induction are taken into account. A more general 
discussion of the discharge of a condenser by # wires arranged 
in parallel is given by the same author in the Aznalen aer 
Physik, 8. 
IN acoustics it is common to measure large intervals of 
pitch in octaves and smaller ones in ‘‘commas.” M. A. 
Guillemin proposes to adopt instead of these units the savart 
and the wil/savart. By the savart is meant an interval of ten 
to one, which equals three octaves plus a major third. The 
millisavart, which is the thousandth part of the savart, repre- 
sents the interval between two French standard diapasons giving 
one beat per second. 
WE have received a reprint from the Astronomical Journal, 
for January, of Dr. G. Johnstone Stoney’s paper on the effect of 
meteoric deposits on the length of the terrestrial day. It deals 
exclusively with the effects so far as they are due to an 
alteration of the moment of inertia of the earth, the object being 
to show that when the earth’s compressibility is taken into ac- 
count the increase in the moment of inertia is much smaller 
than would appear from calculations in which this influence is 
omitted. 
IN a preliminary note contributed to the Azz det Lincez, 9, 
Dr. Quirino Majorana describes certain novel magneto-optic 
phenomena. The analogy of Kerr’s phenomenon has suggested 
that when a substance possessing magnetic properties is placed in 
a field of force, the state of strain set up should give rise to double 
refraction. Dr. Majorana has investigated this magnetic double 
refraction, which he finds exists ina small degree in ferrous 
chloride and to a greater extent in dialysed iron or ferric oxide 
in colloidal suspension. But another phenomenon was observed, 
particularly in solutions of ferric chloride that had acted on 
hydrates of iron. This phenomenon consisted in a rotation of 
the plane of polarisation when this plane was neither parallel 
nor normal to the lines of force. In each case the direction of 
the incident light was perpendicular to the lines of force, and if 
the direction of polarisation was either parallel to or perpen- 
dicular to the lines of force, no phenomenon of the kind con- 
sidered was observed, while, on the other hand, the effect was a 
maximum when the direction of polarisation made an angle of 
45 with these lines, and it consisted in a rotation of the plane 
of polarisation which the author describes as positive when its 
direction is towards the lines of force. For this phenomenon 
the name of bimagnetic rotation is proposed. 
THE report of the director of the Liverpool Observatory for 
the year 1901 has been published, by order of the Mersey Docks 
and Harbour Board, and contains the usual daily results of 
-meteorological and other observations, which are the more 
valuable from the fact that they have been continued and care- 
fully prepared for a long series of years. The Observatory lies 
within the area of the usual tracks of our prevalent westerly 
gales, and this is doubtless one reason for the special attention 
that is given to wind observations ; these embrace anemometrical 
records of the horizontal motion of the air and the extreme 
pressure on the square foot. In addition, the tables show the 
maximum daily velocities recorded on a Dines’s pressure-tube 
anemometer, and thus afford a valuable check on the registra- 
tions of the ordinary instruments. In addition, to the regular 
work of a first-class observatory we observe that telegrams are 
forwarded daily to the Meteorological Office for use in the pre- 
paration of weather-forecasts and storm-warnings, and that 
special observations of clouds are supplied in connection with 
the monthly international balloon ascents, which are frequently 
noticed in our columns. The earth disturbances that have been 
registered during the year have also been carefully collated. 
