April lo, 1879] 



NATURE 



clxixvii 



BARCLAY & SON, 



138, REGENT STREET, LONDON. 



Te Her Majesty and H.R.H. the Prince ef Wales. 



DUPLEX LAMPS. 

 MODERATOR LAMPS. 



READING LAMPS. 



MICROSCOPE LAMPS. 



BEST colza: oil. 



Ai KEROSINE OIL. 



WAX, SPERM, 



AND 



PARAFFINE CANDLES. 



ILLUSTRATED CATALOGUES POST FREE. 



DRAPER'S INK (DICHROIC), 



THE NEW BLACK INK 



DIFFERING FROM ANYTHING ELSE EVER PRODUCED. 

 Writing becomes a pleasure when this Ink is used. It has been adopted 

 by the principal Banks, Public Offices, and Railway Companies throughout 



Ireland. 

 It writes almost instantly Full Black. I Flows easily from the Pen. 

 Does not corrode Steel Pens. Blotting-paper may be applied at the 



Is cleanly to use, and not liable to Blot. | moment of writing. 



Can be obtained in London, through Messrs. Barclay & Sons, Farring- 

 don Street; W. Edwards, Old Change; F. Newbery & Sons, Newgate 

 Street; Wm. Mather, London and Manchester; J. Austin & Co., Duke 

 Street, Liverpool ; and Stacy & Cook, Paternoster Row ; and to be had of 

 all Stationers. 



BEWLEY & DRAPER (Limited), Dublin. 



CHEMICAL & PHYSICAL APPARATUS 



BOTTLES, PURE CHEMICALS, 



And every requirement for Science Classes, Private Study, or Business 

 Purposes. 



Illustrated Priced Catalogues post free for six stamps. 



Carriage allowed to any station in England or Wales, on orders of 40*. 

 value and upwards. 



MOTTERSHEAD AND CO 



7, EXCHANGE STREET, & 10, HALF MOON STREET, 

 MANCHESTER.- 



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 various Public Examinations. 



Portable Chemical Cabinets adapted for privaU study. 



Price Lists on Application. 



DIAMONDS AND OTHER PRECIOUS 



STONES. Scientific opinion givenas to GENUINENESS, PURITY, 

 and VALUE.— BwfCB Wright, 90, Great Russell Street, London, 



MINERALOGY AND GEOLOGY. 



A New List of Collections of Fossils, Minerals, and Rocks now ready, 

 includmg Special Collections to illustrate the various Text-books, in 

 Cabinets. List of Sections if Rocks for the Microscope. Blowpipe Appa- 

 ratus and Materiab of all kinds in Cases or separately. New Patterns of 

 Geological Hammers, with prices. List of New and Second-hamd Books of 



JAMES R. GREGORY, 



MUSEUM OF GEOLOGY. 



88, CHARLOTTE STREET, FITZROY SQUARE. 

 THIN GLASS FOR MICROSCOPIC 



MOUNTING, of best quaUt;. Cycles, v. ^ per ounce ; Sqmares, 

 w. 9<^. ; post free ^. extra ; Ground edged Slips, 51. per gross ; also 

 ether Mounting Materials and Objects prepared for mounting.— CHAS. 

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



GEOLOGY.— In the Preface to the Student's 



ELEMENTS of GEOLOGY, by Sir Charles Lyell, price gx., he says : 

 — " As it is impossible to enable the reader to recognise rocks and mine- 

 rals at sight by aid of yerbal descriptions or figures, he will do well to 

 obtain a well arranged collection of specimens, sach as may be procured 

 from Mr. TENNANT (149, Strand), Teacher of Mineralogy at King's 

 College, London." These Collections are suppUed on me following 

 terms, in plain Mahogany Cabinets : — 



100 Specimens, in Cabinet, with 3 Trays ». ..» .~ J^t a o 

 200 Specimens, in Cabinet, with 5 Trays >m .^ .» 5 5 o 

 300 Specimens, in Cabinet, with 9 Drawers ... ... le 10 • 



400 Specimens, in Cabinet, with 13 Drawers ~. ». 31 o o 

 More extensive Collections at 50 to 5,000 Guineas each. 



MINERALOGY AND GEOLOGY. 



24 assorted Minerals for Blowpipe Experiments, with printed List, in 

 Pocket Case, 2S. ; 24 ditto (second series), 2S. ; Moh's Scale of Hardness 

 of Minerals, 9 Specimens with File and streak tablet in a convenient Case, 

 4J. ; von Kohbell's Scale of Fusibility of Minerals, 6 Specimens in Pocket 

 Case, 2S. ; Geological Collecting Bag complete, 4J. ; Ditto Hammer 

 Holder and Strap, 2s. Geological Charts, Books, Hammers, Chisels, 

 Lenses, Acid Bottles, Glass-capped Boxes, Cement for Mounting and Re- 

 pairing Fossils, Tablets, Card I'rays, &c., &c. Minerals, Fossils,' and 

 Rocks, sent on approval and for selection to all parts of the world. ^ 



THOMAS J. DOWNING, 



38, WHISKIN STREET. LONDON, E.C. 



CATALOGUES FREE. 



ENGRAVINGS AND ELECTROTYPES 



FOR SALE, at prices ranging from is. to zos., in good condition, ready for 

 printing. Small, medium size, and large engravings, comprising a great 

 variety of subjects, suitable for Publishers, Advertisers, and Amateurs. 

 Specimen of any subject required sent post free on application. 



FACSIMILE OF SIGNATURE for jj. An exact copy of any name 

 guaranteed. These signatures being engraved in bold relief, are useful for 

 Stamping Books, Circulars, and Documents, or Marking Linen, and made 

 type-high for ordinary Letterpress Printing. 



Sent post free to any address on receipt of 36 stamps. 



•JS, FLEET STREET, LONDON, E.C. 



ARTISTIC— To Ladies and Gentlemen with 



some leisiure time, desiring to supplement their incomes, an opportunity 

 is offered of acquiring the ART of DRAWING and ENGRAVING 

 on WOOD in a thoroughly satisfactory and perfect style. The terms 

 are moderate, and the hours can be made to suit the convenience of 

 pupils. Persons residing in the country can receive full instruction by 

 correspondence. For further particulars call or address Mr. J. Frank- 

 lin Nash, Artist and Engraver, 75, Fleet Street, London, E.C. 



On the ist of every Month, price Sixpence. 



THE ENTOMOLOGIST: 



AN ILLUSTRATED JOURNAL OF BRITISH ENTOMOLOGY. 



Edited by John T. Carrington, 

 With the Assistance of 

 Frederick Bond, F.Z.S. I Frederick Smith, F.L.S. 



Edward A. Fitch. J. Jesner Weir, F.L.S. 



John A. Power, M.D. | F. Buchanan White, M.D. 



The Entomologist was founded for the purpose of diffusing information 

 with regard to the science generally, and especially respecting Insects in- 

 jurious to Farm or Garden ; for Recording the Capture of Rarities ; and 

 for Figuring Varieties. Monthly Lists of Duplicates and Desiderata are 

 published. 



Interesting articles on all branches of the science are promised by leading 

 entomologists. Especial attention is given to the printing of the Woodcut 

 Illustrations, which are numerous. There are occasionally Coloured 

 Plates. 



SIMPKIN,^^ MARSHALL, and CO. , Sutioners' Hall Court. 



