clxvi 
NATURE 
[DeEcEMBER 18, 1913 
GAS ANALYSIS 
APPARATUS. 
(Manufactured at our own works.) 
FOR 
GAS, ATMOSPHERES, 
MINE AIR, &c. 
- At constant volume 
or 
constant pressure. 
Incorporating latest 
methods of 
absorption and 
combustion. 
Copy of interesting 
list will be sent on 
application to 
ALEXANDER WRIGHT & CO., 
LTD., 
WESTMINSTER. 
SCIENTIFIC INSTRUMENTS 
OF ALL DESCRIPTIONS. 
The “ HARRIS” 
SPECTROMETER. 
|| jweminanam | | 
mesa] ect 
A cheap and reliable Instrument specially designed tor 
Students’ use. 
' Very strongly constructed so that it may be used by 
elementary pupils without being put out of order. 
PRICE £2:10:0 Each Net. 
Descriptive Pamphlet on application. 
PHILIP HARRIS & CO., tro. 
St. Martin's Street, London, W.C., and THe MAacMILLAN Co., 66 Fifth Avenue, New Y 
Atunpum ‘Murries 
In furnaces heated: by electricity Alundum 
Muffles will stand many more heats than the 
ordinary clay muflles and give the furnace 
greater efficiency in operation because of 
their high thermal cozductivity. 
Sole Agents, in the United Kingdom, 
for the Alundum Refractories. 
TOWNSON & MERCER. 
LTD. 
34 CAMOMILE ST., LONDON, E.C. 
POLARIMETER 
ACCESSORY 
FOR INVERSION TUBES. 
CONSTANT TEMPERA- 
TURE HOT WATER CIR- 
CULATION APPARATUS 
(Davies), entirely of copper, 
the gas supply is adjusted by a — 
capsule regulator; and the flow of 
water can also be regulated by a 
screw-clip. The water enters the 
top chamber and passes through a 
copper spiral into the boiler, the 
steam from the boiler is condensed 
and flows back, so that e¢ 
apparatus when once regulated will? 
go on for some considerable time 
without attention. Designed for 
a constant temperature of 87° G.,, 
but can be used up to about 
90° C., and below 87° C. With 
instructions. 
55/- net. 
From our large Chemical 
Apparatus List, page 741. 
No. 4519. 
BIRMINGHAM ee 
. A. GALLENKAMP & CO., Ltd., 19-21 Sun St., London, E.C. 
Prin ted vy yy Ric HAKkD CLay & Sons, Limrrep, at B runswick Street, | Stamford Street, & E., , and published by MAcMILL AN AND Co., ~ LiMiTED, at 
fork. —Tueurspay, December 18, 1913. 
