April z, 1879] 



NATURE 



clxxvii 



ADVERTISING. 

 C. H. MAY cSt CO., 



GENERAL ADVERTISING OFFICES, 

 78, GRACECHURCH STREET, LONDON, E.C. 



(The only Address.) 

 ESTABLISHED 1846. 



Advertisements of every description received for insertion in all News- 

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

 papers. 



Estimates for General Advertising. Reduction for a series. 



Liberal terms to large advertisers. 



Adverusements 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, containing a complete List of Newspapers published 

 in the United Kingdom. Post free, td. 



MICROSCOPIC OBJECTS. 



Horn Sections, Blood Discs, Feathers, Hairs, Sections of Bone and Teeth, 

 Fish Scales, Anatomical Preparations from the Htiman Subject and Lower 

 Animals, Palates of Mollusca, Sections of Shells and Pearls, Polyzoa, whole 

 Insects, Parasites, parts of Insects, Ossicula, Spines, &c., of Echinoder- 

 mata, Spicules of Sponges and Gorgonias, Foraminifera, Botanical Prepara- 

 tions, Diatom a crae. Salts, Crystals, Sections of Rocks, Fossils, Minerals, 

 &C. 



Ocbreous Iron in Moss-like Forms in Calcite, xs. td. post-free. 



Stellar Mica, or Canadian Phlogopite, ix. -^d. post-free. 



Catalogues free. 



THOS. D. RUSSELL, 



48, ESSEX STREET, STRAND, LONDON, W.C. 



JOHN NORMAN, 



MANUFACTURER OF 



MICROSCOPES, OBJECTS, CABINETS, 



TABLES, LAMPS, 



And all Glass Appliances for Microscopes, 



HAS OPENED NEW AND EXTENSIVE PREMISES AT 



123, Queen Victoria Street, E.G. 



Lists post free on application. 



FRY'S 



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." — Food, Water, and Air, 

 edited ty Dr. Hassall. 



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



HOENE'S POMPEIAN DECORATIONS. 

 ROBERT HORNE, 



HOUSE DECORATOR and PAPER-HANGING 



MANUFACTURER, 



41, GRACECHURCH STREET, LONDON, E.C. 



By Special Appointment to His Majesty the King of Italy. 



MICROSCOPES, OBJECTIVEST^ 



CENTENNIAL EXHIBITION, PHILADELPHIA, U.SJL 



The Medal and Highest Award has been given for Design, 

 Construction, Optical Excellence, and Moderation in Price, to 



HENRY CROUCH, 



66, BARBICAN, LONDON, E.C. 



Fully Illustrated Catalogue and full Instructions by Post^ 6 Stanqis. 

 Mailed abroad free. 



BARCLAY & SON, 



138, REGENT STREET, LONDON. 

 To Her Majesty and H.R.H. the Prince of Wales. 



DUPLEX LAMPS. 

 MODERATOR LAMPS. 



READING LAMPS. 

 MICROSCOPE LAMPS. 



BEST COLZA OIL. 



A I KEROSINE OIL. 

 WAX, SPERM, 



AND 



PARAFFINE CANDLES. 



ILLUSTRATED CATALOGUES POST FREE. 



JAMES WOOLLEY, SONS, & CO., 



69, MARKET STREET, MANCHESTER. 



CHEMICAL APPARATUS AND REAGENTS 



For Lecture and Class Demonstration, Laboratory Instruction, &c. 

 SETS OF APPARATUS AND CHEMICALS 



For the yarioiu Public Examinations. 



Portable Chemical Cabinets adapted for priva**. study. 



Price Lists on Ai^lication. 



EUDOLPH KOENIG, 



(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. 



W. L A D D & CO., 

 Scientific Instrument Manufacturers 



(By AppimUmtni to tht Royal ItuHtutian of Great Britain), 



II & 12. BEAK STREET, REGENT STREET, W. 



BYRNE'S PATENT COMPOUND PLATE PNEU« 

 MATIC BATTERY for Cautery and general purposes. 



EDMUNDS' PHONOSCOPE for makuig Vocal VitHa- 

 tions visible in a Vacuum Tube. 



HUGHES' MICROPHONE. 



TELEPHONIC APPARATUS, &c. 



LADD'S IMPROVED SELF CHARGING HOLTZ 

 ELECTRICAL MACHINE, with 4 to 12 Plates, in- 

 closed in a Mahogany and Glass Case. This instrument is 

 immediately arailable in any condition of the atmosphere. 

 Philosophical Apparatus of every Description. 



Jlhutratsd CataUgite, Sixpence. 



