THE ANALYST vii-One of ourreagents intablet formwhich has awide varietyof uSeS as aNALYTICAL CHEMIST required for analytical researchAlaboratory in East Anglia. Work involved will includedevelopment of analytical methods and investigation of avariety of problems connected with chemical production.Applicants must have had minimum of three years’ experiencein analytical work and should be of A.R.I.C. standardpreferable. Salary will be in the range of E400-€700 perannum according to ability and experience. Write statingage and full particulars to Box No. 3770, THE ANALYST, 47,Gresham Street, London, E.C.2.ASSISTANT CHEMISTS required for analytical researchlaboratory attached to Home Counties chemical works.Applicants should have had some experience in analyticalwork.Salary according to experience and qualifications.Write stating age details of qualifications and experienceand salary requirid to Box No. 3771, THE ANALYST, 47,Gresham Street, London, E.C.2.NALYSTS required by a Major Oil Company for itsALondon Laboratory handling a wide variety of problemsaffecting oils greases and special petroleum products. Goodeducation add Honours BSc. degree or A.R.I.C. are essentialqualifications. Those appointed will be required to assist theHead of the Analytical Section in applying standard oil testmethods and special analytical techniques to samples of newand used lubricants, engine deposits, etc. The vacancies carryopportunities for progress for young, energetic men, andinvolve some responsibility for the supervision of others.Salary will be commensurate with qualifications and experi-ence ; conditions of employment include pension and sicknessbenefit schemes.Applicants should write giving full par-ticulars, quoting reference (Z.170G) to Box No. 3772, THEANALYST, 47, Gresham Street, London, E.C.2.“ANALOID” Regd.Compressed ReagentsReacting ConstituentSod. DiphenylamineSulphonate (Oxidised)0.001 8. No. 32 AnaloidsMiddlesbrough,Eng.RIDSDALE & co. LTD.- ~ ~~ ~~ACANCIES exist for Chemists in Products ControlVDepartment. Applicants should possess Higher NationalCertificate in Chemistry or equivalent minimum qualification,and be prepared to work shifts. Excellent Non-contributoryStaff Assurance Scheme facilities available.Apply in writingto the Personnel Manager, Petrochemicals Limited, PartingtonIndustrial Estate, Urmston, Manchester.HE ANALYST. 32 Vols., 191549 bound blue clothTand one decennial index. Excellent cdndition. Fair offersinvited. Some other books and laboratory apparatus. Staterequirements. Write Box 3773, THE ANALYST, 47, GreshamStreet, London, E.C.2.ANALYTICALLY STANDARDISEDSAMPLESNow availableSpecial series of Low Alloy SteelSpectrographic Standards (&.I dia. rods)and Photometric Standards (turnings)List No. 3 6 6 ~ free on request fromBUREAU OF ANALYSED SAMPLESLTD.234, Marton Road, MIDDLESBROUGH llP H JOHNSONS OF HENDON offera series of five test papers ofgreat utility to chemists andmanufacturers for the measure-ment of pH values.UNIVERSALis one paper covering com-pletely the range from pH Ito pH 10 enabling pH valuesto be checked to within 0-5 pH.COMPARATOR test papersmake a set of four separateindicators for obtaining a stillgreater degree of accuracy bydetermining the pH value ofany solution to within 0.3 pH.Descriptive leaflet willbe sent free on requestJOHNSONS OF HENDON LTDLONDON, N.W.4 ESTAB. 1743ON T H E CHEMICAL BOOKS & ALLIED SCIENCESLarge Stock of Recent Editions.Foreign Books. Select Stock. Booksnot in stock obtained under Board ofTrade Licence. Catalogue on requestSECONDHAND DEPT.140* Gower Street, W.C.l.Large Stock of Scientific and TechnicalLiterature availableLENDING LIBRARYScientific and TechnicalAnnual Subscription fromTwenty five ShillingsProspectus post free on requestThe Library Catalogue revised toDecember, 1949. Just Published.Pp. xii + 1162. To subscribers 17s. 6d.net.; to non-subscribers 36s. net, postage 1s.Bi-monthly List of New Books and NewEditions sent post free to subscriberson requestH. K. LEWIS & Co. Ltd.LONDON :136, GOWER STREET, W.C.l.Telephone : EUSton 428