STAINLESS STEELWELDED’ VESSELSThe purpose of the vessel illustrated above i s toeffect the absorption of nitrous gases and theirconversion into nitric acid, and forms part of aninstallation for the manufacture of nitric acid bythe combustion of ammonia under pressure con-siderably above that of the atmosphere. Thesevessels will be installed in a vertical position, areof a total height of approximately 53 ft. anddiameter 6 ft. 6 ins.Specialists in Class I. X-Rayed Heat TreatedFusion Weldings to Lloyds and InsuranceCorn pan ies’ specifications.Booklet gglndustrial Plant” No. 750Csent upon request.For all DutiesEvery improvement discovered by researchor practice i s incorporated in our productsWrite for List No. 3059.1PropylButylAmy1DiacetoneALCOHOLS lsobutylMethylEthyl ACETATES ButylDimethylDiethylDiamylDihexylDioctylP HTH AL AT ES D i WAcetaldehydeButraldeh ydeParaldehydeALDEHYDES CrotonaldehydeAmy1 AldolACETONE ACETIC ACID TRlACETlNACETIC ANHYDRIDE DlACETlNAceto acetic esterMesityl OxideDiethylOxAuTES DibutylButyl STEARATES Amy!EthylOLEATES ButylEthylLACTATES ~ u t y lAmy1Diethyl TARTRATES DibutylTributyl CITRATES TriamylThey are all manufactured in England by :BRITISH INDUSTRIAL SOLVENTS LTD.WELBECK HOUSE, DOWNS SIDE, BELMONT.SURREY TELEPHONE : VIGILANT 0133-4iiV @ c p.3.brand ofSul pharsp henaminefor intramuscular injectionPrepared and tested in accordance with the Therapeutic SubstancesRegulations 1931 under U.K.Manufacturing Licence No. 18.SULPHARSAN i s a sodium salt of a methylenesulphurous acidderivative of 3: 3’-diamino-4: 4’-di hydroxyarsenobenzene. It consistsmainly of a sodium salt of 3 : 3’-diamino-4: 4‘-dihydroxyarsenoben-zene-NNN’-trimethylene-sulphurous acid and is a light yellow, free-flowing powder.SULPHARSAN dissolves easily and completely in water, giving asolution nearly neutral in reaction. Such a solution causes no painon injection and is well tolerated. It is unnecessary, therefore, touse special solvents for Sulpharsan.Disappearance of spirochaetes within 48 hours and rapid normalhealing of the lesions follow the use of this product.Each batch i s clinically tested before issue.Approved by the Minister of Health for the purposes of the PublicHealth (Venereal Disease) Regulations, 1916.Issued in ampoules of 0.15 : 0.3 : 0.45 : 0-6 grm.For further particulars apply toL i v e r p o o l : H o m e M e d i c a l D e p a r t m e n t , Speke, L i v e r p o o l , 19London: H o m e Medical Department, Bartholomew Close E.C.IMade in England b yE V A N S S O N S L E S C H E R & W E B B L T D . M . ~ ~SOUTH-WEST ESSEX TECHNICALCOLLEGE AND SCHOOL OF ART(Essex Education Corn mittee)FOREST ROAD, WALTHAMSTOW, E.17Principal :H. LOWERY, M.Ed., Ph.D., D.Sc., F.1nst.P.SCIENCE DEPARTMENTHead of DepartmentR. W. JUKES, B.Sc., A.R.I.C., F.C.S.Senior lecturer i n chemistry :H. HOLNESS, M.Sc., F.R.I.C., M.I.T.Senior Lecturer in Physics :J. BOR, M.Sc.Tech., F.1nst.P.Full-time Day Courses extending over 3 or 4 years areheld in preparation for the London University B.Sc.,General and Special Degrees in Chemistry, Physics, Botany,Zoology, and Mathematics ; also for A.R.I.C.and A.1nst.P.Many research investigations are in progress in theScience Department and students may become associatedwith any of these with a view to taking either the M.Sc.or Ph.D. Degree.Part-time Degree and National Certificate Courses arealso available in Science subjects.Special facilities are available for the study of industrialapplications of science, e .g., plastics, radiology, electronics,chemical engineering.The College was opened in 1938 and replaces the formerLeyton and Walthamstow Technical Colleges.The building is entirely new and the equipment up-to-date.In addition to excellent teaching accommodation,the College possesses ample social amenities, viz., concerthall with cinema and stage, swimming bath, two gymnasia,library, refectory, writing and private study rooms, andcommon rooms.Full particulars and Prospectus of classes may be obtainedon application to the Principal.viTHE POLYTECHNICRegent Street London, W.1DEPARTMENT OF CHEMISTRY &? BIOLOGYHeadofDepartment : H. LAMBOURNE, M.A., M,Sc., F.R.I.C.DAY AND EVENING COURSESB.Sc. Degree Special and General (External), LondonUniversity .Associateship of the Institute of Chemistry (A.R.I.C.)Diploma.Intermediate Science Course in Chemistry, Botany,Zoology, and Physics, suitable for Medical, Dental,and Pharmacy students.Prospectus free on application to theDirector of EducatioiiviiTHEROYAL INSTITUTE OF CHEMISTRYOF GREAT BRITAIN AND IRELANDThe Institute of Chemistry was established in 1877 to providethe Government and the public with the means of recognis-ing those who have been properly trained and proved to becompetent to practise chemistry as a profession.In 1885 theInstitute was granted a Royal Charter with authority to grantcertificates of competency, and to register persons qualifiedto practise. The aims of the Institute include the elevationof the profession of chemistry and the maintenance of theefficiency, integrity and usefulness of persons practising thesame, by compelling the observance of strict rules ofmembership, and by setting up a high standard of scientificand practical efficiency.Particulars of the Regulations and Examinations of theInstitute can be obtained (free) on application, to-THE REGISTRARTHE ROYAL INSTITUTE OF CHEMISTRY30 RUSSELL SQUARE, W.C.1Large departments for Books onChemistry, Physics and all Branchesof Science.FOYLESFORNew and Second-hand Books onEvery Subject. Nearly 3 millionVolumes in Stock. Books Bought.119-125 CHARING CROSS ROAD,LONDON, W.C.2Open g a.m.-6 p.m., including Saturday.TcIcfihonc: GERrard 5660 (16 lines).XThe fact that goodsmade of raw materialsin short supply owingt o w a r conditions a r eadvertised in this Bookshould not be takenas an indication thatthey a r e necessarilyavailable for exportTHE SEAL OF SATISFACTIONREFRACTOR1 ES forR ES I STA N C ECONDUCTANCECONSERVATIONofH €AT r- STEEL I I FURNACES ISILICA 1-11 ck!!KJ!!!!c I SILICEOUSSILLIMANITE“DO M E*’ I NS u LATI 0 NI F:L::E:s I D.S.F.REFRACTORY MATERIALS ARE INDEMAND FOR MANY INSTALLATIONSCOVERING A WIDE RANGE OFI N D USTRl ESTHE DERBYSHIRE SILICA FIREBRICKTelegrams : Telephone :SILICA, FRIDEN, HARTINGTON. 60, LTD. HARTINGTON 230.FRIDEN : HARTINGTON : BUXTONxTHE EDWARDS TYPE IVCOMPRESSOR AND VACUUMPUMPVACUUM :- - - - - 24 inches Hg.DISPLACEMENT: 3 cubic feet per minute.PRESSURE:- - - - - - -1Olbs.This ' general-purpose ' o u t f i t fulfils long-standing require-ments in works and laboratories.It i s compact and quiet,and can be easily adapted to meet special needs.f 1 8 : 18 : O PRICE COMPLETEAS ILLUSTRATEDBLOWPIPES FILTRATIONSSPRAY I N G CI RCU LATl NGAS PI RATi N G, etc.W. EDWARDS & CO. (London) LTD.MAKERS OF VACUUM PUMPS, PLANT AND GAUGESKANGLEY BRIDGE ROAD, LOWER SYDEN H A MLONDON, S.E.26Telephone: Telegrums:SYDenham 7026 (P.B.X.) Edcohivac, Phone, London.xiWOUNDS,BURNS etc.HEAL RAPIDLY andTURN SEPTICI f TREATED WITHOINTMENTBECAUSE one or other or all of the three races of germs, Streptococci,Staphylococci, and B. pyocyaneus are found in every skin in-fection common to this country, and ANTIPEOL OINTMENTcontains the antibodies (antivirus) of these germs. Healing isexpedited by the proved ingredients of the ointment, andseptic development is stopped or prevented by its antivirussterile vaccine filtrates.ANTIPEOL OINTMENT is unsur-passed for BURNS and SCALDS, for it is microbicide and non-adhesive, and dressings do not require to be changed every day.RHINO-ANTIPEOLaffords rapid relief of COMMON COLDS, INFLUENZA, ANDCATARRH. Containing the antibodies of the germs commonto infections of the nose and pharynx (Staphylococci, Strepto-cocci, B. pyocyaneus, pneumococci, pneumobacilli, entero-cocci, M. catarrhalis, B. Pfeiffer), Rhino-Antipeol is not just apalliative, but is a remover of the cause of the infection. Duringepidemics it is the ideal preventative of microbic development.OPHTHALMO-ANTIPEOLis a semi-fluid ointment, more convenient than the ordinaryAntipeol ointment for ocular infections and lesions.Eyesaffected by smoke and dust are soothed almost immediatelyby the application of Ophthalmo-Antipeol, and the antivirusprevents germs from developing.C l i n i c a l S a m p l e s o n r e q u e s t f r o mM EDlC 0-B I 0 L OG ICA L LAB ORATO RI ES LTD.CARGREEN ROAD, SOUTH NORWOOD, LONDON, S.E.2SCIENTIFIC BOOKSH. K. LEWIS & Co. Ltd.A very large selection of new and standard works in everyThe Department for Scientific Books, English and Foreign, is onthe first floor.Foreign Books not in stock obtained under Licence.Orders and Inquiries by Post promptly attended to.branch of Science always available. (Lift to First Floor).Underground : Euston Square, Warren Street.‘Buses : Euston Road and TottenhamCourt Road.SCIENTIFIC LENDING LIBRARYAnnual Subscription, Town or Country, from One GuineaThe LIBRARY is useful to SOCIETIES and INSTITUTIONS, andto those engaged on SPECIAL RESEARCH WORK, etc. TheLibrarv includes all Recent and Standard Works in all branches ofMediAl and General Science.Reading and Writing Room (first floor) open daily.New Books and New Editions are added to the Library and areavailable to Subscribers immediately on publication.Catalogue of the Library, revised to December 1943 ; containingthe titles of books arranged in alphabetical order under the Author’snames, with size, price and date, and an Index of Subjects with thenames of the Authors who have written on them.To Subscribers 12s 6d. net ; To Non-subscribers 25s. net. Postage 8d.Quarterly List of New Books and New Editions is issued free to allSubscribers and Bookbuyers regularly.Detailed Prospectus on Application.Every work is the latest edition.~~ ~~~~ ~ ~STATIONERY DEPARTMENT : Scient& and General.SECOND-HAND BOOKS: 140 COWER STREET.Large and oaried stock.Books not in stock sought for, and reported when found.H. K. LEWIS dk Coo Ltd.PUBLISHERS AND BOOKSELLERS136 COWER STREET, LONDON, W.C.lTelegrams : Telephone :‘PUBLICAVIT. WESTCENT. LONDON.’ EUSton 4282 (5 line)xWelded Fabrications in Steel,Stainless Steel and otherMetal