Oct. 2, 1879] 



NATURE 



clxxxvii 



FRYS 



GOLD MEDAL, 

 PARIS EXHIBITION. 



COCOA 



In Packets and Tins. Pure 

 Cocoa only, with the super- 

 fluous oil extracted. 



EXTRACT 



"If properly prepared, there is no nicer 

 or more wholesome preparation of 

 cocoa." — Foodf Water ^ and Azr, 

 ediUd by Dr, Hassall. 



J, S. FRY & SONS, Bristol and London. 



JOHN NORMAN, 



MANUFACTURER OF 



MICROSCOPES, OBJECTS, CABINETS, 



TABLES, LAMPS, 



And all Glass Appliances for Muroscopes, 



HAS OPENED NEW AND EXTENSIVE PREMISES AT 



34, Whitecross Street, Cripplegate, E.G. 



Lists post free on application. 



ADVERTISING, ~~ 



C. H. MAY <S6 CO., 



GENERAL ADVERTISING OFFICES, 

 78, GRACECHURCH STREET, LONDON, E.G. 



(The only Address.) 

 ESTABLISHED 1846. 



Adverti«ements of every description received for insertion in all News- 

 papers, Magaiines, Reviews, &c., at the same rates as at the offices of the 

 papers. 



Kstimates for General Advertising. Reduction for a series. 



Liberal terms to large advertisers. 



Advertisements are also received for all newspapers, which may be ad- 

 dressed to these Offices, without extra charge, and replies forwarded, if 

 required. 



C. H. MAY & CO., having special communication with the leading news- 

 papers three times daily, can guarantee the utmost promptitude and correct- 

 ness of insertion to all Advertisements entrusted to them. 



The Press Manual for 1B79, containing a complete Li:;t of Newspapers 

 pablished in the United Kingdom. Post free, td. 



THIN GLASS FOR MICROSCOPIC 



MOUNTING, of best quaKty. Circles, %s. 6d. per ounce ; Squares, 

 2X. 9^. ; post free ^d. extra ; Ground edged Slips, 5;. per gross ; also 

 other Mounting Materials and Objects prepared for mounting.- CHAS. 

 PETIT, 151, High Street. Stoke Newington, N. 



ELECTRICAL APPARATUS. — Science 



Teachers, Lecturers, and Amateurs, should send for Special Reduced 

 List. FRICTIONAL APPARATUS of new patterns and improved 

 insulation. HOLTZ MACHINES, warranted reliable in all weathers, 

 from ^4. Large set of Brass Induction Conductors, 2 12-inch Cylin- 

 ders, Sphere, Biot's Hemispheres, dj-inch, ebonite mounted, 50.;. Large 

 Uranium Glass Aurora Tubes. POWERFUL LEYDEN BAT- 

 TERIKS, new construction, half cost of usual jars. VOLTAIC AP- 

 PARATUS. — Batteries, Quart Bunsen's, 4^-. and 4J. 6rf. j-gallon 

 Bichromate, 12 Cells, in Case, £%. Grove and all other Cells. AI EOI- 

 CAL BArrERIES. ELECTRIC LAMP for lantern use, /6 65. ; 

 action equalling the most expensive. Cheaper Lamps. Coils, own 

 ' make, i-inch Spark, 75^. Bells, Wires, Carbons, and all requirements. 



F. H. BROOK, 107, Lorrimore Road, London, S.E. 



MINERALS, ROCKS, AND FOSSILS. 



COLLECTIONS IN CABINETS. 



Two Hundred Specimens, 40J. ; 150 do., 30J. ; 100 do., aoj. ; 50 do., loj. 

 Sixe of Specimens, 2 square inches. Naming and Localities guaranteed. 



Superior Cabinets fitted with Card-Trays and Catalogue included. 



" The Popular Scientific Pocket Cabinet Series '* comprises 9 Cabinets and 

 224 Specimens. 2j. 6ti. each Cabinet, free delivery, ^d. (See Natlre, 

 March 13. No. 489, page 447.) 



The Collector's lield Apparatus complete, 2it. Hammer-holder and 

 Waist-strap, price 2/. Collecting-bag (figured and described), price 4;, 



THOMAS J. DOWNING, Geologist, &c., 



I 38, WHISKIN STREET, LONDON, E.C. 



' Catalogue, Lists, and " Quarterly Circular *' free on receipt of 2d. postage, 



ASTRONOMICAL TELESCOPES.— 



CALVER'S REFLECTING TELESCOPESof the highest excellence, 

 from sj-inch to 36-inch aperture. sJ-inch, with equatorial moli'^n, 

 £iS ^S^' ; 6-inch Equatorial, complete; Photo, with Calver's " Hints 

 on Silvered Glass Reflecting Telescopes," 9 stamps.— G. CALVER. 

 F.R.A.S.. Hill House, Widford, Chelmsford. 



FoR SALE —A very fine isJ-inch Equatorial, with Cbck. 



EUDOLPH KOEiNIG, 



(DR. PHIL.) 

 MANUFACTURER OF 



ACOUSTICAL INSTRUMENTS. 



TO ILLUSTRATE THE LAWS 



AND TO PRODUCE THE PHENOMENA OF SOUND. 



PARIS. 26, RUE DE PONTOISE. 



PRICE LISTS FREE. 



CASTLETON, DERBYSHIRE. 

 JOHN TYM 



Has largely added to his stock of Fossils and Minerals, and is now oflfering 

 greatly improved Educational Collections at very Low Prices. 



For full particulars see his Catalogue, sent post free on application. 

 Postal Address — 

 CASTLETON vid SHEFFIELD. 



NATURAL HISTORY STORES. _ 



4S, ESSEX STREET, STRAND, W.C. 



Students and others are invited to inspect THOMAS D. RUSSELL'S- 

 Collections of British and Foreign Shells, Corals, Zoophytes. Annelids,, 

 Crustacea, Echinoderms, Minerals, Fossils, Rock Specimens, Microscopic 

 Objects, &c. 



Cabinets, Geologist's Hammers, Glass Capped Boxes, Card Trays, 

 Tablets, Glass Slips, Micro- Thin Glass, Canada iSalsam, Marine Glue, ami 

 other requisites for the Geologist and Microscopist. 



Catalogues Post Free. 



MINERALOGY AND GiiOLOGY. 



COLLECTIONS TO ILLUSTRATE THE ABOVE SCIENCES, 

 FROM 4J. ' 



SINGLE SPECIMENS FROM 3^, 



AUGITE, ENSTATITE, GLAUCODOT, NEOTOKITE, CHOM- 

 DRODITE, VERY FINE; NORWAY. 



PHENACITE, TOPAZ, ALEXANDRITE, BERYL GROSSULAR, 

 SIBERIA. 



A SMALL QUANTITY OF THORITE WITH ORANGITE, 



BLOWPIPE CASES, HAMMERS AND CHISELS, AND CRYS- 

 TAL HOLDERS. 



FBITATE LESSOKS AND ETEKINO CLASSES. 



The next course of Ten Lessons will conunence WEDNESDAY, October 



Sth, 7.30. Fee 10s. 



CniaJogites/ree. 



SAMUEL HENSON, 

 277 {Late 113a), STRAND, LONDON, W.C. 



Now ready, price is. fd. 



A SYSTEMATIC COURSE of PRACTI- 



CAL QUALITATIVE ANALYSLS. By THOMAS ELLOFT, 



F.C.S., F.I.C. 



The above work is specially arranged for Advanced Students preparing for 



the Science and Art Departments' Practical Chemistry Examination, to be 



held in May, 1880; also for the First B.Sc. , Preliminary Scientific, 0.\ford 



and Cambridge Local Practical E,vaminations. 



Specimen Copy, post free, 15 Stamps. 55, Torriano Aventie, London, 



See Reviews— C<«m;V«/ Ne;vs, September n, 1879; !ichooltnastery 

 August 30, 1879. 



London : SIMPKIN, MARSHALL, & CO. 



DIAMONDS AND OTHER PRECIOUS 



STONES. Scientific opinion givenai to GENUINEN ESS, PURITY 

 and VALUE.— Brvce Wright, 90, Great Rusiell Street, London. 



DIAMONDS IN MATRIX. 



R. C. NOCKOLD, Diamond and Oriental Stone Cutter and Dealer, ha* 

 for sale specimens of the above; also Cut Precious Stones in all Colours. 

 12, FRITH STREET, SOHU, W. 



ELECTRICAL and SCIENTIFIC APPA- 

 RATUS. — MICROPHONES and HUGH ES' SONOMETER, 

 ELECTRIC BELLS. INDICATORS. Kirc and Thief-Al.^rms. New 

 Constant Batteries, INDUCTION-COILS and FRICTIONAL 

 MACHINES, Magnets, Insulated Wires, Screws, and all materials. 

 Liberal Tbrms to Schools and Sciemch Teachers. Apparatus 

 on hire. Complete Electric Catalogue, a stamps, optical and Photo- 

 graphic List, I stamp.— DALE and CRAMPTON, Manufacturing. 

 Electricians, 4, Little Britain, London, E.C. 



