Feb. 27, 1879] 



NATURE 



CXXXl 



MINERALOGY AND GEOLOGY. 



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

 Pocket Case, is. ; 24 ditto (second series), zj. ; 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, 2J. ; Geological Collecting Bag complete, 4J. ; Ditto Hammer 

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

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

 pairing Fossils, Tablets, Card Trays, &c., &c. Minerals, Fossils, and 

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



THOMAS J. DOWNING, 

 38, WHISKIN STREET, LONDON, E.C. 



CATALOGUES FREE. 



SHEPPEY FOSSILS. 



W. H. SHRUBSOLE, Shkerness-on-Sea, respectfully intiniates thai 

 the appeal recently made by him has been so heartily responded to, that he 

 cannot receive any more orders for " extra selected " specimens at present. 



Orders for io.t. Collections of 100 "good" specimens can be executed 

 without delay. 



" VOTES ON THE GEOLOGY OF SHEPPEY " post free on xpfVi. 

 cation. 



THE 



MONTHLY JOURNAL OF SCIENCE 



AND ANNALS OF 



BIOLOGY, ASTRONOMY, GEOLOGY, INDUSTRIAL ARTS, 

 MANUFACTURES, AND TECHNOLOGY. 



Edited, by WILLIAM CROOKES, F.R.S., &c. 



Now Ready, the Number for March, 1879. 

 Price ONE SHILLING and SIXPENCE. 

 I. The Keys of Death. 

 II. A Curious Th?rmo-Magnetic Motor. By Prof. Edwin J. Houston 

 and Elihu Thomson. 



III. The Heat of the Comstock Mines. By Prof. John A. Church, 



EM. 



IV. Matter Active. 



V. Some New Optical Illusions. By Sylvanus P. Thompson, B.A. , 

 D.Sc.,F.R.A.S. 

 VI. On Electrical Insulation in High Vacua. By William Crookes, 

 F.R.S. (Illustrated). 

 VII. Spiders' Web for Micrometers. 

 VIII. The "Jumi)ers" or " Jumping Frenchmen." 

 Correspondence. — The Character of the Sexes. — ^Transformation of Species. 

 Reviews of Scientific Works — Science Notes — Proceedings of Scientific 

 Societies. 



London: 3, Horse-Shoe Court, Ludgate Hill, E.G. 



LA SEMAINE FRANCAISE : Journal 



Francais pour I'Angleterre : Politique, Litterature, Sciences, Arts, 

 \ Varietcs, Nouvelles, et Notes. Un exemplaire par ia poste, »,\d., en 



timbres poste. Abonnement franco par la poste — un an, i8j. ; six mois, 

 gj. ()d. Piix 4(/., chei tons les libraires et aux gares des chemins de fer. 

 On s'abonne aux bureaux, 37, Southampton Street, Strand, Londres, 

 W.C. 



LA SEMAINE FRANCAISE.— "'La Semaine Fran- 



caise ' has been brought out in London for the benefit of those English 

 readers who may wish to study contemporary French fi-om all points of 

 view, instead of confining their reading to one particular Gallic print. 

 It certainly merits success." — Graphic. 



LA SEMAINE FRANCAISE.— For Students. 



LA SEMAINE FRAN gAISE.— For aU who read and 



speak French. 



LA SEMAINE FRANCAISE. 



LA SEMAINE FRANCAISE.— For Teachers and 



Schools. 



LA SEMAINE FRANgAISE.— For General and 



Family Reading. 



LA SEMAINE FRANCAISE. 



LA SEMAINE FRANCAISE.— "Tel est le titre d'un 



journal hebdomadaire, nous pourrions dire d'une revue de tous les jour- 

 naux fran9ais accredit^s. Ce journal reunit, sous le meme convert, 24 

 ou 32 pages grand format, et dans ces pages sont publics, en fran9ais, 

 les meilleurs articles, politiques, critiques, et litteraires, qui ont paru 

 pendant la semaine dans les journaux de Paris. Assur^ment le numero 

 que nous avons sous les yeux est un excellent specimen de ce que peut 

 faire un heureux choix, guide par une intelligence parfaite de ce qui peut 

 int^resser les lecteurs." — NouvelU Chronigue de Jersey. 



LA SEMAINE FRANgAISE.— "The numbers before 



us are ftill of good things It will be far better for most than any 



u one of the best papers published in Paris itself. We are much pleased 

 with the character of it, and believe it will be highly valued in all those 

 many households where French is cultivated. 'Ihe printing is very well 

 done." — Queen. 



LA SEMAINE FRANgAISE: a Weekly Newspaper 



and Review in the French Language. Politics, Literature, Science, 

 Art, Varieties, Notes. Price ^d. , through booksellers, and at the rail- 

 way bookstalls. Office, 37, Southampton Street, Strand, W.C. I 



NEW MONTHLY GEOGRAPHICAL 

 PERIODICAL. 



Will be Published on MARCH ist, the Third Number of 



THE PROCEEDINGS OF THE ROYAL GEOGRAPHICAL 



SOCIETY, AND MONTHLY RECORD OF GEOGRAPHY. 



Published under the Authority of the Council, and £klited by H. W. Bates, 

 Assistant-Secretary. 



Contenis. 



The Road to Merv. By Major-General Sir Henry C. Rawlinson, K.C B 



With Map. 

 The Basin of the Helmund. By Clements R. Markham, C B. With Map. 

 Books and Memoirs on Zulu Land. 

 Maps of Zulu Land. 

 Geographical Notes. 

 Obitiiary. 

 Correspondence. 



Report of the Evening Meetings. 

 Proceedings of Foreign Societies. 

 New Books. 

 New Maps. 



Price to Non-Fellows, is. 6d. 



EDWARD STANFORD, S5, Charing Cross, S.W. 



NORTH BRITISH AGRICULTURIST, 



Is the only Agricultural Journal in Scotland, and circulates extensively 

 amongst landed proprietors, factors, farmers, farm-bailiffs, and others 

 interested in the management of landed property throughout Scot.aa<i and 

 the Northern Counties of England. 



The AGRICULTURIST has also a very considerable circulation on the 

 Continent of Europe, America, Australia, and the Colonies. 



The AGRICULTURIST is pubhshed every Wednesday afternoon in 

 time for the evening mails, and contains Reports of all the principal British 

 and Irish Markets of the week, besides telegraphic reports of those held op 

 the day of pubhcation. 



The Vetoinary Department is edited by one of the leading Veterinarians 

 in the country, and is invaluable to the breeder and feeder as a guide to the 

 rearing of animals, and their treatment when labouring under disease. 



Full Reports are given of the Meetings of the Royal Agricultural Society 

 of England, the Royal Agricultural Society of Ireland, the Highland and 

 Agricultural Society of Scotland, the Scottish Chamber of Agriculture 

 and all the principal Agricultural Associations throughout Great Britain 

 and Ireland. 



For Advertiseis addressing themselves to Farmers a better medium does 

 not exist. 



Price yi. By post, i^d. Annual Subscripdon, payable in advance, 14*. 



Office. — 377, High Street, Edinburgh. 



Post-Office Orders payable to Charles Anderson, Jun., Exiinbuigh. 



Established 1843. 



THE BREWERS' GUARDIAN: 



A Fortnightly Paper devoted to the Protection of Brewers* Interests 



Licensing, Legal, and Parliamentary Matters. 



Review of the Malt and Hop Trades ; and Winb and Sfisit Tkabk 



Record. 



The Organ of the Country Brewers. 



" The Brewers' Guardian ' is published on the evenings of every alternate 



Tuesday, and is the only journal officially connected with brewing interesu. 



Subscription, i6i. 6d. per annum, post free, dating from any quarter-day. 

 Single Copies, if. each. Registered for transmission abroad. 



Offices -5. Bond Court, Walbrook, London K.C. 



MICROSCOPES, OBJECTIVES, &c. 



CENTENNLAL EXHIBITION, PHILADELPHIA, U.S.A. 



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. 



Folly Illustrated Catalogue and full Instructions by Post, 6 Stamps. 



Mailed abroad free. 



TO THE SECRETARIES OF NATURAL HISTORY 

 MUSEUMS AND SCIENTIFIC SOCIETIES. 



BRYCE-WRIGHT'S CATALOGUE. 



This important risumi will be forwarded post free to the 

 Secretaries of Societies and Museums, upon application, for the 

 general use of such Institutions. 



90, 



BRYCE-WRIGHT, 



GREAT RUSSELL STREET, BLOOMSBURY, 

 LONDON, W.C. 



