NA TURE 



[December 30, 1922 



NOTICE, — In consequence of the 

 Holidays the issue of NATURE 

 for the week ending January 6 

 may not be in the hands of Sub- 

 scribers and others until Saturday, 

 instead of Friday, as usual. 



The number will begin a new 

 volume and contain, in the series 

 of SCIENTIFIC WORTHIES, 

 an article on Prof. H. A. Lorentz, 

 For.Mem.R.S., accompanied by 

 a separate photogravure plate 

 portrait, proofs of which, on India 

 paper, will be published at 5s. net. 



ST. MARTINS STREET, LONDON, W.C.2. 



UNIVERSITY OF LONDON. 



The Senate invite applications for the UNIVERSITY CHAIR of 

 ZOOLOGY tenable at Ileilford College. Salary ^800 a year. Applica- 

 tions (12 copies) must be received not later than first post on April 16, 1923, 

 by the Academic Registrar, University of London, South Kensington, 

 London, S.W.7, from whom further particulars may be obtained. 



THE QUEENS UNIVERSITY OF 

 BELFAST. 



DEPARTMENT OF PHYSICS. 



APPLICATIONS are invited for the LECTURESHIP in PHI 5I( S. 

 Salary ,6450 per annum. 



Particulars of the appointment may be had from 



J. M. FINNEGAN, Se. retary. 



EAST LONDON COLLEGE 



(UNIVERSITY OF LONDON). 



CHEMICAL DEPARTMENT. 



Professor—]. R. Partington, M.B.E., D.Sc. 



DEMON'S rRATOR required foi January is. Special qualifii ati. ns in 

 Organic Chemistry. Appointment for two terms in the fir-t instance. 

 Salary ^125-^150 a term, according to qualilications. Applications should 

 be forwarded at once. 



E, J. WIGNALL, Registrar. 



APPRENTICES.— The Firm of C. BAKER 



(Established 1765), Scientific and Optical Instrument Manufacturers, 

 have vacancies on their staff for 2 Apprentices. A unique opportunity 

 ed for. a thorough training, both technical and . 

 C. BAKER, .741 High Holborn, Lond 



presente 



The Misses FARRAN 

 10 Bell Yard, Temple Bar, W.C.2, 



HAVE CONSIDERABLE EXPERIENCE IN 



COPYING SCIENTIFIC MS. 



AND ARE PREPARED TO 

 UNDERTAKE ANY QUANTITY. 



DUSTLESS ROOMS 



isiFLORIGENE- 



DURING the VACATION for BEST RESULTS 



The Dust-Allayer " Co. 



4 VERNON PLACE, BLOOMSBURY, LONDON, W.C. 1. 



THE HANDBOOK OF 

 PATENT LAW OF ALL COUNTRIES 



By W. P. THOMPSON, F.C.S.. M.I.Mech.E.. Etc., 

 Chartered Patent Agent of Liverpool. 



Entirely revised and rewritten 1920. 157 pages. Crown Octavo. 

 All Countries, 6s. British Law only, Is. 



"Should prove a very valuable and trustworthy guide to would-be 



Lo 



Sons, Lit 



MESSRS. SOTHERAN 



have now opened a Scientific Department on the first floor of 

 their Strand House, where a selection of their large stock in 

 modern, as well as old and rare, works on Exact and Applied 

 Science may be seen on the shelves. 



They would also call attention to their facilities in getting sets 

 or runs of periodicals on scientific subjects, as well as rare or 

 out-of = print books they may not have in stock already. 



HENRY SOTHERAN & CO., 140 Strand. W.C.2, & 43 Piccadilly, W.i, London. 



LEWIS'S 



CIRCULATING LIBRARY 



of Scientific, Technical, 

 and Medical Books 



covering the widest range of subjects, pure and applied. 



NEW BOOKS and EDITIONS are added In UNLIMITED SUPPLIES, 



as long as the demand requires, delay or disappointment thus 



being prevented. 



ANNUAL SUBSCRIPTION iTown or Country FROM ONE GUINEA 



according to the number of books required at one time. 



Subscriptions may commence from any date. 



Books may be retained as long or exchanged as frequently as desired. 



The READING AND WRITING ROOM (first floor) is open daily. 

 Prospectus, with Quarterly List of Additions, fostfree. 



H. K. LEWIS & CO. Ltd., 



Euston Square Station. 



1 Place, 



:iy;-: Warren Street. 



