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November 25, 1915] 



NATURE 



-etti- 



HIGH-CLASS POLARIMETERS 



With or without 



spectrum attachments 



for 



rotatory dispersions. 



"Price List " M " of 

 'Polarimeters post free on 

 application to the Makers : 



ADAM HILGER, 



LTD., 



75a CAMDEN ROAD, 



LONDON, N.W. 



Telegrraphic Address : 

 ** Sphericity, Camroad, London." 

 Telephone Number: 1687 North. 



THE BRITISH DRUG HOUSES 



supply 



ANALYTICAL REAGENTS 

 "A.R." 



The B.D.H. Analytical Reagents 

 are guaranteed to conform to the 

 standards of purity regarded as 

 necessary for analytical work by 

 the Special Committee appointed 

 by the Councils of the Institute 

 of Chemistry and the Society of 

 Public Analysts. 



Professional Chemists are re- 

 quested to specify B.D.H. when 

 ordering "A.R." chemicals 

 through dealers. 



Price List will be sent on application. 



THE BRITISH DRUG HOUSES, Ltd., 



Chemical Manufacturers, 

 Graham Street, City Road, London, N. 



COX'S 



INDUCTION COILS 



FROM 1 TO SO INCHES SPARK 



For Research, Demonstration, X-rays, etc. 



The illustration shows a New i>j'C </. Sinall Coil, 

 especially suitable for Experimental Work. It is fitted 

 with a Variable High-speed Interrupter that works 

 on any voltage up to 200. Very heavy discharge. 



HARRY W. COX & CO., Ltd., 



159-161 GREAT PORTLAND STREET, LONDON, W. 



FACTORY : QROSVENOR WORKS, WESTMINSTER. 



