NOTICES TO CORRESPONDENTS. ALL communications relative to advertisements, post-office orders, and orders for the supply of this Journal, should be addressed to the PUBLISHER. All contributions, books, and pamphlets for the EDITOR should be sent to 192, Piccadilly, London, W. To avoid disappointment, contributions should not be received later than the 15th of each month. No notice whatever can be taken of communications which do not contain the name and address of the writer, not necessarily for publication, if desired to be with. held. We do not undertake to answer any queries not specially connected with Natural History, in accordance with our acceptance of that term; nor can we answer queries which might be solved by the correspondent by an appeal to any elementary book on the subject. J. W. H.-The pretty flowers sent are those of the "Milkwort" (Polygala vulgaris), pink and blue varieties. F. G., Norwich.-Your query is difficult to answer, but on the whole it is possible that the Chaffinch, having a more general distribution, is more numerous than the House Sparrow; that is, taking the country through. L. T.-You are quite right,-the moss is Pottia truncata. F. C.-See last number of SCIENCE-Gossip, Dr. Knaggs's article on "Collecting and Preserving." The larvæ in public collections are preserved by professionals, who keep their mode of working as secret as possible.-C. G. B. H. M. J. H.-A first-class work on British Diptera (illustrated) is that by Mr. Francis Walker, F.L.S., published by Reeve, Covent Garden. A NEW SUBSCRIBER, Torquay.-Your query respecting storm-glasses should have been sent to some publication devoted to physical rather than to natural science; but we will endeavour to answer it. The instruments usually sold are closed at the top, and have a brass cap cemented over them. We have made them of Eau-de-Cologne bottles, and after filling, simply corking them. We never heard of any opening being left; in fact, if there were, the fluid would quickly evaporate. They, as you are probably aware, are perfectly useless as indicators of the weather, and the crystalline changes that take place are most probably due to changes of temperature. If you push the cork a little way into the tube and pour a little asphalt varnish on the top of it, you will find it will seal up the opening effectually. H. G. WISE. We cannot without seeing the instrument assign a reason for the imperfect illumination of the field in your binocular. Try a piece of fine ground glass between the object-slide and the condenser; this will diffuse the light and very materially add to the stereoscopic effect. Our instrument performs well even with as high an objective as a when the ground glass has a strong pencil of light condensed on the under surface. J. G., jun., Londonderry.-Colloid Silica can be obtained by dialysing a preparation of silicate of soda (which may be procured at most chemists). This is decomposed by hydrochloric acid, and the liquid is placed in a dialyser, and the dialyser placed in pure water. After the lapse of a short time the crystalline material passes through it, leaving the colloid si ca behind. A diyser resembles a little tambourine, and is made of a ring of gutta-percha, over which is stretched parchment-paper (writing-paper will do). The dialyser is floated in a vessel containing distilled water.-F. K. DIATOM. We think A. would suit you best. A SUBSCRIBER, Ashburton.-Immersion lenses are made on a principle devised by Amici, which was adopted by Hartnach and Nachet of Paris, and several of the American opticians, but did not find favour here until the last few years, when the advantages of objectives constructed on the immersion principle began to be recognized. An immersion lens is so called from the circumstance of a drop of water being placed between the front lens and the object itself, on the thin covering glass, so that the rays leaving it pass through a film of water instead of air. It is well known that the loss of light from the reflection of oblique rays from a surface of glass is much less when they pass from water into glass than from air into glass. Immersion objectives require special corrections for the purpose, and are useless if used as an ordinary dry lens. Our leading opticians are therefore adapting an extra front combination to the ordinary high power, by means of which they can be used either as wet or dry lenses. Several papers on the construction and advantages of immersion lenses will be found in the Monthly Mic. Jour.-F. K. H. H., Leeds.-The Water-beetle is Hydroporus depressus, recently out of pupa. Your specimens were smashed. They ought to have been enclosed in a cork cell, or in a quill or small box. J. S. D.-Instruments, &c., for egg-blowing may, we should think, be obtained at any first-class philosophical instrument maker's, &c. G. B.-The plant sent is Neottia nidus-avis. A. A. C.-We cannot tell what is the best food for birds in aviaries, unless we first know what kind of birds are kept. F. F. M.-Specimens mislaid. Numbers 1 and 2 are difficult to determine. They are the midribs of sea-weeds; but we cannot tell the species. Number 3 is a zoophyte, Membranipora pilosa. JOHN LE BAS.-The specimens were not exuviæ of fishes, or anything organic. No organic remains whatever are found in mica-schist. The specimens seem to us to be decomposed felspar, with a proportion of iron. A WORKING MAN.-You had better ask us some definite question in our "Notes and Queries," and you will have no difficulty in obtaining an answer. Z. E. G.-Your mosses were named in last month's issue. J. C. K.-The specimens attached to the Clematis branch are not cocoons, but the female of a species of Coccus, or "Scale insect," which has been introduced into this country. Like the Cochineal insect, the body of the female becomes the shelter for the young, the mother dying to provide them with this protection. The eggs may be seen underneath the scale. THOMAS ROMANS.-The fungus on the leaves of Ragwort is an Ecidium. See Cooke's "Microscopic Fungi," coloured illustrations. London: Hardwicke, 192, Piccadilly. ANONYMOUS We beg to draw the attention of several of our correspondents to our rule of not answering questions unless accompanied by the real name and address. EXCHANGES. NOTICE. Only one "Exchange" can be inserted at a time by the same individual. The maximum length (except for correspondents not residing in Great Britain) is three lines. Only objects of Natural History permitted. Notices must be legibly written, in full, as intended to be inserted. STROMBUS, Cypræa, and other foreign shells, for British Marine shells.-A. W. Langdon, Llanrwst House, Hastings. LIVING Dytiscus or Colymbetes offered for slide of clean diatoms.-H. E. Freeman, 1, Rose Villas, Wood Green. For palate of Cyclostoma elegans send stamped and directed envelope to J. H. Martin, 86, Week Street, Maidstone. EGGS of Red-footed Falcon, Grasshopper Warbler, Scoter, Crested Grebe, Eared Grebe, Sclavonian Grebe, Pintail, Longtail, Scaup, and Eider Ducks, Sandwich Tern, &c., for others. T. H. Phuler, Vale Royal, Northwich, Cheshire. A WELL-MOUNTED Tongue of Bee, for Diatoms from Guano, mounted and named.-H. B. Thomas, 13, Market-place, Boston. WILL A. C. A., Post Office, Staines, kindly send a list of his duplicate eggs to T. H. Phuler, Vale Royal, Northwich, Cheshire? FOR Flustra foliacea send stamped directed envelope to P. Smith, Legh Street, Warrington. FOR Gemellaria loriculata send stamped envelope and object to Miss E. de B. Meyrick, Downshire Lodge, Blessington, Co. Wicklow, Ireland. CYCLOSTOMA elegans and Helix Pomatia in exchange for other English shells.-B. F. Buxton, Easneye, Ware. FOR exchange or otherwise, an excellent Englishin.objectglass of 120 degrees angular aperture, in perfect condition.Apply to the Rev. J. Bramhall, St. John's Vicarage, near Lynn, Norfolk. VALLISNERIA, Frog-bit, Lemna trisulca, Drosera, Chelifers or Petrobii, for marine or fossil diatom material.-J. G. R. Powell, Matlock Bridge. COMMUNICATIONS RECEIVED FROM F. K.-F. P.-C. J. L.J. H. G. (M.D.) G. E. X.-T. S.-W. H. P.-T. L.-S. A. B.W. E. S.-T. C. O.-W. H. G.-J. G. R. P.-J. B.-A. W. L. -J. H. M.-H. E. F.-W. S.-T. H. P.-H. B. T.-E. D. F. M. -B. F. B.-R. H. A.-Dr. H. F. P.-J. R. D.- E. J. T.C. A. R.-E. W.-J. R. S. C.-C. L. W.-R. H.-J. G.-J. T. -H.-Dr. C. C. A.-J. D. L. T.-J. R. J.-F. B. B.-G. H. H. -M. A. D.-C. A. R.-R. H. W.-J. H. C. C. S.-G. O. H.H. E. B. JAMES L. DENMAN, WINE MERCHANT, Importer and Introducer of GREEK and HUNGARIAN WINES, 20, PICCADILLY, LONDON, Solicits a trial of the following PURE and UNBRANDIED WINES, which for price and quality cannot be surpassed :— GREEK BURGUNDY (Red and White) possess all the qualities of the finer sorts of French Burgundy, and are most strongly recommended for their body, flavour, and bouquet. Unapproachable at the price.-In quantities of not less than four dozens....... Single dozen.... ..... (per doz.) 15s. Od. LA GAUPHINE CLARET, a full-bodied South of France Wine.-In quantities of not less than four dozens. Single dozen 16s. Od. (per doz.) NATURAL SHERRY, from CADIZ, a very clean and nice dry Wine, without acidity.—In quantities of not less than four dozens. (per doz.) Single dozen...... .... 9s. 6d. 10s. 6d. 158. Od. 16s. Od. (Can be tasted free.) The above Wines will greatly improve with age in bottle; are very full-bodied and clean on the palate; are admirably adapted for luncheon and dinner, and will upon trial be found, from their distinctive characters, to fulfil every domestic requirement. I can most confidently and conscientiously recommend them to your notice as being pure and free from added spirit (either at home or abroad), as beneficial to the system, and unsurpassable at the price. Cases and bottles to be returned or paid for. Cross Cheques National Bank. Detailed Priced Lists forwarded on application. JAMES L. DENMAN, 20, PICCADILLY, LONDON. Now ready, Demy 8vo., nearly 500 pp., elegantly bound in cloth, with an Illustrated Map, price 3s. 6d. THE INTERNATIONAL EXHIBITIONS' GUIDE For 1872. COMPRISING A GUIDE TO THE INTERNATIONAL EXHIBITION. Together with Remarks Descriptive of Former Exhibitions at Home and Abroad, and of Various Processes in Manufactures; also a Miniature Guide to London and its Environs. LONDON: JOHN LANE & CO., 9, BOUVERIE STREET, E.C. In Preparation, Fep. 8vo., fully Illustrated. GEOLOGICAL STORIES. A PIECE OF GRANITE. A PIECE OF SLATE. A PIECE OF LIMESTONE. A PIECE OF SANDSTONE. A PIECE OF ROCK-SALT. Being the Autobiography of A PIECE OF JET. A PIECE OF PURBECK MARBLE. A PIECE OF CHALK A LUMP OF CLAY. A PIECE OF LIGNITE. THE CRAGS. A BOULDER. THE STORY OF A GRAVEL-PIT. By J. E. TAYLOR, F.G.S., Author of "Half-hours at the Seaside," &c. LONDON: ROBERT HARDWICKE, 192, PICCADILLY, W. "By a thorough knowledge of the natural laws which govern the operations of digestion and nutrition, and by a careful application of the fine properties of well-selected cocoa, Mr. Epps has provided our breakfast tables with a delicately flavoured beverage which may save us many heavy doctors' bills." Civil Service Gazette. GRATEFUL-COMFORTING. EPPS'S (BREAKFAST) COCOA. Each Packet is Tin-lined and Labelled JAMES EPPS & CO., HOMEOPATHIC CHEMISTS. Errs's Cocoa is also prepared with condensed milk, and sold in tins labelled "ErrsS'S MILKY COCOA." 650 pp., Fcap. 8vo., price 68. SCIENCE AND COMMERCE; THEIR INFLUENCE ON OUR MANUFACTURES. A Series of Lectures and Statistical Essays descriptive of the chief Articles of Commerce, and the Progress of our great Manufacturing Industries. BY P. L. SIMMONDS, Editor of the Journal of Applied Science, &c. CONTENTS. THE OBLIGATIONS OF COMMERCE TO SCIENCE, AND THE INDUSTRIAL AND MANUFACTURING USES OF PROGRESS OF SCIENTIFIC DISCOVERIES IN THE NINE- THE COTTON MANUFACTURE:-Production and Con- THE WOOLLEN Manufacture:-The Wools of Com- THE IRON MANUFACTURE:-Progress of our Metallic THE GLASS MANUFACTURE. EARTHENWARE AND PORCELAIN. DYES AND COLOURING STUFFS :-Animal Dyes-Vege- THE LEATHER TRADE AND TANNING SUBSTANCES. STATISTICS OF THE IMPORTS OF DYE-STUFFS AND THE MANUFACTURE OF, AND TRADE IN, PRECIOUS THE TRADE IN GROCERIES. THE OIL AND COLOUR, CONFECTIONERY, TOBACCO, NUTS, THEIR PRODUCTS AND USES. NEW PAPER-MAKING MATERIALS AND THE PAPER LONDON: ROBERT HARDWICKE, 192, PICCADILLY, W. PROCÉDÉ DE REPRESENTATION DIT PHYTOXYGRAPHIQUE. HERBIER DE LA FLORA FRANCAISE, Par M. L. CUSIN, Aide Naturaliste au Jardin Botanique de Lyons. ET M. E. ANSBERGUE, Veterinaire Militaire. MR. HARDWICKE begs to inform British Botanists amd all who are forming a Library, that he has been appointed sole Agent for the above very splendid FLORA OF FRANCE, to be completed in Twenty Volumes, Seven of which are now ready, and may be seen at 192, PICCADILLY. Each plant is printed from the Natural specimen, with dissections at foot, the flower being coloured. The number printed being very limited, an early inspection is invited. 192, PICCADILLY, January, 1872. LONDON INTERNATIONAL EXHIBITION OF 1872, Admission Daily, One Shilling; except on Wednesdays, 2s. 6d., and on certain Reserved Days. MILITARY BANDS DAILY AT FOUR IN THE ROYAL HORTICULTURAL GARDENS SEASON TICKETS-Gentlemen, £2. 2s.; Ladies, £1. 1s. HARDWICKE'S SCIENCE-GOSSIP. MICROSCOPIC ROYAL HORTICULTURAL SOCIETY'S M1 ARRANGEMENTS FOR 1872. MEETINGS and EXHIBITIONS on the following dates, viz. :July 3rd and 17th, Aug. 7th and 21st, Sept. 4th and 18th, Oct. 2nd, Nov. 6th, and Dec. 4th. Permanent Exhibitions of Flowers, Plants, and Shrubs will also be made during the year by some of the leading nurserymen. Band of the Royal Horse Guards, or other bands, on all the above dates, also Promenade and Band every Saturday throughout the Year. Schedules of Prizes for the various Exhibitions at South Kensington, as well as for the Society's great Provincial Show at Birmingham, are now ready, and can be had on application to J. RICHARDS, Assistant Sec., Royal Horticultural Society, South Kensington, W. N.B. The principal Shows of the Society at Kensington are those on May 15th and 16th, June 5th, 6th, and 7th, and July 3rd. lxxxi OBJECTS (Unmounted). 24 First-class Specimens, carefully prepared, with Instructions for Mounting, sent for 3s. by WALTER WHITE, Litcham, Norfolk. THE IMPROVED "DAMAR," Prepared by W. WHITE, Is the Best substitute for Canada Balsam. AGENTS: London: Mr. Baker, 244, High Holborn, W.C. Manchester Mr. Daneer, Optician. Bristol: Messrs. Hatch & Co., Opticians. Hull: Mr. Gibson, Chemist. Ipswich. Mr. Wiggin, Chemist. Price 1s., postage 1d. TO GEOLOGISTS AND COLLECTORS OF FOSSILS. Great ZOOLOGICAL GARDENS, REGENT'S PARK, FNorthern Bazaar, No, 243, Pentonville-road, King's Crom, OPEN DAILY (EXCEPT SUNDAYS). FIRST CLASS MICROSCOPIC OBJECTS. MARTIN BURGESS, 3, Mount Pleasant Terrace, Upper Lewisham Road, S E. Section of Bone of Cuttle Fish. Now Ready, price 2s. 6d. PRACTICAL PHYSIOLOGY; A SCHOOL MANUAL OF HEALTH: Being an Introduction to the Elementary Principles of Physiology, and a Practical Guide to the means of securing Health and Life. Intended for the use of classes and for general reading. By EDWIN LANKESTER, M.D., LL.D., F.R.S., late Lecturer on Physiology, St. George's School of Medicine, London; late Superintendent of the Government Food Museum, South Kensington; and Medical Officer of Health, St. James's, Westminster. Fifth edition, with numerous Illustrations and Questions for Examination, Tables, and Glossary. "I have no hesitation in saying it is just what we require. I know of nothing which contains anything like the same amount of prac tical (elementary) information in the same compass; and it is written in so simple and easy a style that the knowledge it conveys will be more readily assimilated and utilised."—Dr. Rumsey. London: ROBERT HARDWICKE, 192, Piccadilly. Mackenzie's Educational Books, INTENDED FOR SCHOOLS OR SELF-INSTRUCTION. MACKENZIE'S TABLES. Complete, price 2d.; cloth, 6d. MURRAY'S ENGLISH GRAMMAR. price 2d.; cloth, 4d. Complete, MAVOR'S SPELLING. Price 4d.; or, 2 parts, 2d. each. HARDWICKE'S ELEMENTARY BOOKS, PRICE TWOPENCE EACH. OPTICS. Fully illustrated. Complete, 4d.; cloth, 6d. ROBERT HARDWICKE, 192, Piccadilly, London. London, a Choice lot of Saurians, &c., from Blue Lias, and Trilobites, &c., from Silurian Lime. G EOLOGY.-ELEMENTARY COLLECTIONS to illustrate the modern works on Geology, and facilitate the interesting study of Mineralogy and Geology, can be had at 2, 5, 10, 20, 50, to 1,000 guineas; also single specimens of Minerals, Rocks, Fossils, and Recent Shells, Geological Maps, Hammers, Models of Gold Nuggets, all the recent publications, &c., of J. TENNANT, Mineralogist to Her Majesty, 149, Strand, London, W.C. PRACTICAL INSTRUCTION is given in MINERALOGY and GEOLOGY, by Mr. TENNANT, F.R.G.S., at 149, Strand, Illus. trated by numerous Specimens, Models, Diagrams, &c. MICROSCOPIC OBJECTS. THOMAS D. RUSSELL has for SALE an interesting Series of Preparations from the Echinodermata, Mollusca, Foraminifera, &c. Palate of Squid (Loligo vulgaris), opaque or for polariscope. Post-free, 13 stamps. The New Catalogue of Collections and Specimens of British Shells, Fossils, Echini, Crustacea, &c., post-free on application to THOMAS D. RUSSELL, 37, Arundel Street, Strand, London, W.C. Is the only BUILDING SOCIETY whose Annual Receipta exceeds HOW TO PURCHASE A HOUSE HOW TO PURCHASE A PLOT OF LAND NEW WORKS PUBLISHED BY ROBERT HARDWICKE, 192, PICCADILLY. Half-Hours at the Seaside. By J. E. Taylor, F.G.S. Small 8vo., with about 150 Illustrations. Price 4s. plain, 6s. coloured. Hardwicke's Handy-book of London: a Plain and Compre hensive Guide to Everything worth Seeing and Hearing in and around the Metropolis. CONTENTS:-Amusements-Bazaars-Bridges-Cemeteries-Churches and Chapels-City Halls and Companies-Colleges-Commercial Edifices-Criminal Courts-Docks-Free Exhibitions-Government EdificesHigh Churches-Hospitals-Law Courts-Learned Societies and Institutions-Libraries-Markets-Monuments and Statues Museums and Antiquities-Music Halls—Omnibuses—Outdoor Amusements-Palaces-Parks and Gardens-Picture Galleries-Popular Entertainments-Popular Preachers-Principal Thoroughfares—Railways— Steamboats-Theatres. Practical Physiology: a School Manual of Health. Being A Practical Guide to the means of Securing Health and Life. Intended for the use of classes and general reading. By Dr. LANKESTER, F.R.S. Fifth Edition. Fcap. 8vo., price 2s. 6d. Illustrated. "It is copiously illustrated. There is not a school of any kind for males or females, rich or poor, in which the book might not be used as a text-book; indeed, it ought to be as common as an English Grammar. Few persons are capable of forming an idea of the increase of human happiness and material prosperity which would follow a more general appreciation of the laws of health."-Lancet. Degrees and "Degrees; or, the Traffic in Theological, Medical, and other "Diplomas" Exposed. By the Rev. HENRY BELCHER, M.A., Assistant Master in King's College School. Dedicated, by permission, to the Rev. Alfred Barry, D.D., D.C.L., Canon of Worcester, Principal of King's College, London. Demy 8vo., price 1s. 6d. The Shilling Peerage, Shilling Baronetage, Shilling Knightage, and Shilling House of Commons for 1872. The Complete Peerage, Baronetage, Knightage, and House of COMMONS. In One Volume. Half-bound, with coloured edges, for marking the different divisions. Price 5s. Plain Directions for dealing with an Insane Patient. By J. M. WINN, M.R.C.P., &c., Senior Physician to the St. George's and St. James's Dispensary. Crown 8vo., price 1s. Ben Rhydding, the Asclepion of England. Post 4to., price 1s. The Foot and its Covering, with Camper's Essay on the Foot. By JAMES DOWIE. New Edition, dedicated to Sir W. Fergusson, F.R.S. Price 2s. 6d Oral Training on Scientific Subjects. By H. Bernard, Prin cipal of Lincoln School, Menneapolis. Crown 8vo., price 2s. 6d. The Royal Guide to the London Charities, 1872-3: show ing in alphabetical order their Name, Date of Foundation, Address, Objects, Annual Income, Chief Officials, &c. By HERBERT FRY. Crown Svo., price 1s. 6d. [Shortly. Sowerby's English Botany Is now complete in 83 parts at 5s. each. Eleven Vols. cloth, price £22. 88.; in half morocco, £24. 12s.; whole morocco, £28. 3s. 6d. LONDON: ROBERT HARDWICKE, 192, PICCADILLY. |