NATURE 



[June 24, 1922 



'<m<'m<'A<yXvX'>K'm 



1765 



ivXyX'/X'/X-Xi'/X'/X'/Wv. 



1922 



JUST OUT 



THE JUNE 'SSUE 

 OF OUR 



SECOND-HAND 



OPTICAL & SCIENTIFIC INSTRUMENT 



(including Cameras and Piiotograpliic Accessories) 



CATALOGUE 



pi Containing: about 2,500 items f^ 



'm all in perfect order ; many in new condition. 5: 



'<v. Post free on request. 5S 



^ Apparatus Bought, Exchanged, or Sold on Commission, jg 



SCIENTIFIC INSTRUMENTS 



OF ALL DESCRIPTIONS. 



LABORATORY 

 APPARATUS 



Beakers 



Burettes 



Condensers 



Crucibles 



Evaporating Basins 



Flasks 



Filter Papers 



Nitrometers 



Test Tubes 



Thermometers 



Tubing 



Etc. Etc. 



(1913) 



PHILIP HARRIS & CO., ltd: 



BIRMINGHAM 



(ENGLAND) 



TOWNSON & MERCER 



(Established 1798) 



Manufacturers of Apparatus for 



CHEMISTRY, PHYSICS, MECHANICS, 

 BACTERIOLOGY, METALLURGY, 



and all Science Subjects. 



Sole Agents in the United Kingdom for Becker's Sons 

 (Brummen) Balances and Weights. 



Townson & Mercer have a staff of glass blowers 

 on the premises, and are in a position to supply most types 

 of blown-glass apparatus from stock, while they are 

 prepared to make special apparatus to clients' drawings 

 or particulars. 



34 Camomile Street, London, E.C.3. 



ESTABLISHED 1880. 



A. GALLENKAMP & Co., Ltd. 



Telephone : Telegrams : 



London Wall, 1404 & 1405. Gallenkamp, Finsquare, London. 



WRITE FOR NEW LIST 



OF 



VISCOSITY 



AND 



FLASH-POINT 

 APPARATUS 



As editorially noticed in NA TURE, June i 7, 

 P' 793? '^ ^^Py of wliich will be sent post free. 



19 & 21 SUN STREET, FINSBUEY SQUARE 

 LONDON, E.C.2. 



Printed in Great Britain by R. & R. Clark, Ltd., Brandon Street, Edinburgh, and published by Macmillan & Co., Limited, at St. Martin's Street, 

 London, \y.C.2, and The Macmillan Co., 66 Fiftli Avenue, New York.— Satukoav, June 24, 1922. 



