compound, its only components being India rubber and sulphur, combined by the pressure of steam. This substance has many advantages over real jet. It is equally black, more tenacious, and consequently more suitable for watch guards. It is also more easily worked, being manipulated while hot, and is not more than one tenth the price of jet. Vulcanite became the rage for a time, and jet fell to disuse. But the manufacturers of vulcanite not satisfied with their victory over genuine jet, fell into evil ways, and succumbed to the great temptation to adulterate the genuine vulcanite. The addition of litharge and whiting cheapened the vulcanite considerably, and for a time did not interfere with its appearance; But the pernicious effects of the alloy soon tells, and the "jetty black" of vulcanite turns to a faded green. The vulcanite rage passed over and fashion in its reaction from the sombre ornaments flew to the opposite extreme, and set up a "silver mania." There are now signs that this is on the wane, and the leaning for oxide of gold, by which the rapid transition from jet to silver, among the masses, was slightly interrupted, does not seem likely to come in favor again. In this state of matters, says the Colliery Guardian, comes the announcement from Whitby that there are signs of a revival in the jet trade. The indications of a resuscitation of the industry are certainly tangible.-Scientific American. Does the Didymium of Samarskite differ from that of Cerite?-Lecoq de BoisbaudvanThe author concludes that both give alike the three blue rays, 482-2, 475-8, and 469·1. New Spectral rays in substances extracted from Samarskite.-Lecoq de Boisbaudvan-On examining with the spectroscope both by absorption and by means of the electric spark, the products of his operations on the mixture of earths from Samarskite, the author has observed rays or bands not to be referred to any element formerly known, and not corresponding to the descriptions of the spectra of the earths recently announced by M. M. Delafontaine, L. Smith, Saret, and De Marignac. These new rays of absorption and emission seem to belong to one and the same body. The emission of spectra is composed of four bands shaded towards the left, and formed of narrow rays, the strongest of which is the most refrangible and forms the right margin of the band. The absorption spectrum comprises two strong bands in the blue, and several rays of less importance in the green. The metal which yields these new spectra is precipitated as a double potassic sulphate along with didymium; its simple sulphate is rather less soluble than that of didymium; its oxalate is precipitated along with didymium, but ammonia separates the oxide of the new metal before that of didymium. Samarskite specimens, 50 cents. to $5.00. Fragments, 10 cents. to 50. -Am. Jour. Sci. Associated with above are: Euxenite, 35c to $5.00. Rogeriite, 25c. to $3.00. I make a specialty of rare species. Rock Crystal Lapidary in Japas. His As in all Japanese houses, the floor is raised from the ground a foot or more. The univer sal manner of sitting even when at work, on the hams, is shown with variety in disposing of the feet. Sometimes a man will take a seat on his knees and heels, another will prefer the crosslegged style. The appliances of work are extremely simple, and skill, patience, and hereditary pride make up for any seeming lack of labor-saving tools. Heredity is an important factor in Japanese labor. In many of the villages the crack workmen trace their pedigree back, both of skill and blood, to from three to twenty generations. I once employed a carpenter whose forefathers-as the records of the village temple of his sect in which he and they worshiped, showed-had followed the same trade for twenty-six generations. On the floor we see a man standing, who has been out on the hills digging out the rude quartz. hammers and picks, with which he breaks off, pries out, or digs up the rock, lie on the coarse rice straw mat on the earthen floor. Having secured a basketful and borne the pieces to the lapidary on his shoulder, he cleanses them of adhering gravel or bits of rock. He then passes them over to the "splitter,”- -an old fellow, too old to go bareheaded in the shop any longer, like the younger men, who may be his sons. The old man's part of the work is to break off the long bars of rock into bits the gross size of a ball or bead to be made therefrom. Laying the piece on a large stone, covered with a piece of matting, with the end of calculated length to be broken off protruding over the edge of the stone, a sharp, quick blow with a steel edged hammer, usually severs it. On larger and thicker pieces a gutter is first picked out around the surface sufficiently deep before the final blow is struck. Skill and a "knack" are of great account in this process. On one side of the old man lies a basket of these truncated prisms, which he hands over to the man who rounds them off, into rough globes. This is done by careful_chipping with a tiny steel-edged hammer. It is astonishing how, with simple skill, the man will make an almost perfect sphere. with one very ordinary tool. He soon learns the mysteries of the planes of cleavage, where to tap lightly, where heavily, when to chip, and when to pound. The rough coated balls are now passed to the grinder, who has a tub of water, and four or five partly cylindrical pieces of cast iron a little over a foot long, and looking like reversed graters. These are of different sizes and curves, according to the size of the ball to be ground. His grinding material consists of powdered garnets of various degrees of coarseness. He uses water plentifully, and dex. terously keeps the balls turning, so as to make the surface spherically square. In some cases the ball is fixed in the end of a bamboo tube, and the grinding finished by whirling it, between the palms, in a half spherical iron or stone socket. The globe is now smooth, but the perfect polish has yet to be done by the patient rubbing with the tip of a bamboo cane, and then in the hands with cloths dipped in crocys or rouge, a native oxide of iron. This produces a splendid lustrous surface, and the gem is ater clear, and as refractive to the morning light as a drop of dew that nestles in the heart of the lotus. Clear quartz crystals, 5c. to $5.00. Clusters, 25c. to $100. Slag Wool. "Slag wool," produced as a fine fibre of silica, by blowing steam through the slag of the iron furnaces, has been woven by Messrs. Jones, Dade & Co. into strips and sheets. This excellent non-conducting substance can now, therefore, be very generally applied for clothing boilers or the conducting steam pipes of machinery. In appearance this peculiar "wool" is like spun glass or asbestos, bound together with fine wire. The discovery of this additional method of utilising such a waste substance, as slag was long considered to be, is only another proof of the untiring energy and persistence of our practical scientists. Analysis of Furnace Slag. Manganese .. Calcic sulphide 100.18 As another example, we may recall how but a short time ago experiments proved the feasibility of making glass from slag. After many experiments, an inventor succeeded in utilising the material, and also the heat from the furnaces, and an English company formed to work his patent erected glass-works in Northamptonshire, close to a set of blast furnaces, and are now in operation. The slag flows into a tank at one end, and is there mixed with the required ingredients for making the glass, fused, and fined; the melted metal then flows through a bridge to the other end of the tank, where it is worked, and afterward blown into bottles, &c. As the slag is already melted, it does not require so great a heat for the combination with the other substances, and also it furnishes more than half of the material of the glass. Thus this glass costs less than that made by the ordinary method. The natural tint of the product is greenish, but it can be bleached or colored at will. The furnace now at work produces 90 gross of bottles a day. It can Pele's Hair. BY PROF. JAMES D. DANA. American Journal of Sciences, August, 1879. The capillary volcanic glass of Kilauea, collected by the writer at the volcano, in the year 1840 was analyzed for the writer's Geological Report of the Exploring Expedition (1849) by Prof. B. Silliman (B. Silliman, Jr.), and the results are published in it on page 200. The large discrepancies between the two analyses there reported pecially the difference as to soda, one being stated to one of a dark and the other of a pale variety, and escontain 21-62 per cent, and the other none, left the question of composition in great doubt. I have now to report two new satisfactory analyses of the glass. For these, science is indebted to F. J. Allen of the Sheffield Scientific School of Yale College, excepting the determination of the state of oxidation of the iron, which is by Prof. O. D. Allen.. The results were as follows: Si O Pelés Hair, Alg03 Fe2O3 Feo MnO MgO West Rock"trap" 110-68 2·15 039 063-99-72+P2O50.14 ready known, proving that there was no difference in An important paper on the microscopic characters of readily be seen that it will be cheaper for rof. N. H. Winchell, of the University of Minnesota : Thanks for your little Catalogue. It shows a vast amount of very careful work, and condenses mineralogy into marvelously small space. I have had to consult it seve The above will probally take the place of Asbestus in many manufactures. It cannot however take the place of the long fibred chrysotile, in the weaving of silk fabrics. Fine ral times already in my class work in blowpipe, for names, broad satiny chrysotile in serpentine from &c., not found in Dana's regular edition. Canada, 25 cents. to $2.00, Asbestus, 5 cent s to $1.00. that are only found mag6. In give. Having now letters on file from over 7,000 different correspondents all over the world, most of whom are customers, my facilities for getting anything desired on short notice are unsurpassed, and I doubt if they are equaled. Collecting every mineral at the localities where it is found in the best specimens and the greatest abundance and in ton quantities where possible,most species can be furnished at lower rates than they have hitherto been sold for. I spent over $5000 at the Amazon stone locality alone. A few of the Seymour collections still on hand and offered for sale at halfMr.Seymour's prices Anexamination of the. character of my elementary collections and the minerals sold in quantities, will show that they are far lower than hitherto advertised by other dealers. The accurate labelling of every specimen is guaranteed. As the correct naming of the specimens will be the most important part to many who will see this Catalogue, I feel myself justined in mentioning that I have been a collector of minerals for eighteen years; that I was a student under Prof. Wolcott Gibbs, at Cambridge, and Prof. A. Hoffman, at Berlin. I was also Instructor in Michigan University and Professor in Iowa State Agricultural College, in Chemistry and Mineralogy, for six years. I shall always make a specialty of collecting new and rare specimens. Amazon Stone, Twinned Crystal, In preparing this Catalogue it has been my aim to make it of such value that no chemist or mineralogist, whether amateur, student or Professor of Mineralogy or Chemistry, would feel as if he could afford to be without it, and in doing this, I have spared no expense, either in the way of illustration or labor. The articles on Microcline or Amazon Stone, Barcenite, Hydrotitanite, Schorlomite, Protovermiculite, Variscite, New Fairfield Minerals by Brush & Dana, Astrophyllite, Mica, Feldspar, Quartz, Diamond, Jet, Leidyite, Coeruleolactite, Paramorphs of Rutile after Brookite, Randite, etc., etc., are worth three times the price. My previous Catalogue received the highest commendation from scientific men everywhere (see the note by Prof. Winchell on title page). In this I have corrected some mistakes found in the other, and more than quadrupled the amount of purely scientific matter. Attention is called to the fact that, owing to the fine print used, it contains more than double the amount of matter of most books of same size. A new book containing so much purely scientific matter has very rarely if ever before been published for $1.00. Over 30 of the pages cost me from $15.00 to $25.00 each before a single copy was printed. Every engraving and wood-cut used was made expressly for me, except the few used to illustrate Feldspar, and part of those illustrating crystallography, which are from Dana's Manual of Min. and Lith., price $1.75. The stock now consists of over 50 tons and over 400,000 specimens, mainly crystallized, and such massive things as Agate, Chlorastrolite, Schorlomite, etc., Every specimen in my establishment is plainly labelled with the price, species, species number, and in most cases the composition also. Nine-tenths of the specimens are labelled with printed labels that cannot be removed except by long soaking. There is no variation from the marked prices, except where over $5.00 worth is taken in specimens, worth 25 cents or under, or over $10.00 worth is taken of specimens worth $1.00 each or under, or over $25.00 worth of specimens worth $5.00 each or under. When these amounts are taken a discount of ten per cent. is given. Larger discounts on $100 worth taker at one time. Correspondence especially solicited with deales, miners. or collectors The above discours are not given on minerals by the pound, or on systematic collections. I aim to put ali the specimens at the lowest possible price, and these discounts are made simply because it is almost tle trouble to sell $25.00 worth of $1.00 specimens as is $5.00 worth of 25c. specimens. The printed price is affixed so that customers may know that, unlike most other dealers in this line, I do not vary my prices from time to time as occasion demands or the individua asks. It also guarantees to every individual who ex changes with me that they will get exactly the sar prices as if they gave cash. I will also allow any I son buying any article to return it within one we and take anything else they wish to the same amou or refund their money, less ten per cent to pay for the trouble of handling (if they are not satisfied). Of course, if mistakes are made or the articles are not exactly as represented, themoney will be refunded without deduction, on the return of the articles, or others sent in place, as may bepreferred by the customer. Giving up a lucrative profession to go into this business because I liked it, I have not been disappointed, and now expect to continue in it throughout life, and hope that my children may continue it after me. I do not believe that I can afford to have any customer dissatisfied, and prefer to lose rather than to have any person feel that I have not treated them justly. It will always be taken as an especial favor if any cause of dissatisfaction is immediately reported to me. My success has been due to the kind recommendations of the leading scientific men everywhere. A few of their commendations are given, and hundreds of others might have been added: E. S. Dana, in a letter says; "I wish you every success, and consider that you have done a great deal toward the extension of a knowledge of mineralogy in this country." From the late President of American Association for the Advancement of Science· Louisville, Ky., Aug. 15, 1878 PROF. FOOTE-Dear Sir: It is with great pleasure that I consent to your using my name for reference, as being of great use, both to the scientific and amateur naturalist. Yours Truly, J. LAWRENCE SMITH. I have received similar letters from Prof. S. F. Baird, and many others. University of the State of Missouri, Columbia, Mo., Nov. 4, 1878. PROF. A. E. FOOTE-My Dear Sir. I feel that all scientists owe you a debt of gratitude for your labors in bringing together so vast a collection of minerals, and selling them so cheap that every student of science Yours, &c., may have a collection. G. C. SWALLOW, Dean of Tech. Faculty. See references in advertisement. No such list of Mineralogical books as those in this Catalogue has ever been offered for sale before to my knowledge, and a few out of a large number of pleasant letters are appended. University of Ohio, Columbus, O. PROF. FOOTE -The books came to hand all correct, and you have my thanks for promptness. The books are a bargain. Yours very truly, PROF. S. W. ROBINSON. Sandwich, IU. PROF. A. E. FOOTE:--Invoice of books came to hand all right. Original cost when published $9.00 per vol. Now the set of 3 vols. cost only $5.00. Books are in excellent condition, paper superior, illustrations capital, print very fine indeed. A good bargain; an inexpensive method of obtaining valuable editions of a classical character, and, the best of all, so cheap. Respectfully yours, NAHUM A. BALLOU, M.D, We No. 410 East 26th Street, New York. My Dear Sir:-We get the BULLETIN, and it is a matter of surprise that so much can be gotten into so small compass. The books ordered by Prof Arnold came O. K., and the price was remarkably low can get no such quotations from second hand dealers here. M. N. MILLER, M. D. Very respectfully, Deinonstrator of Practical Physiology. A. E, FOOTE, M. D, 1223 Belmont Ave., Phila., Pa. The systematic collections, of which over 5000 have been sent all over the world, are sold at less than one quarter what any such collections were sold at before we commenced business, and are still more than twice as good as any one else furnishes at the same price. A few letters referring to them are annexed. Mrs. Richards of the Natural History Committee of the Society for the Encouragement of Studies at Home: "The collections are indispensable,and are highly apThank you for the trouble preciated by the students you have taken." Windham, Ohio. I received the amateur PROF. FOOTE-Dear Sir: collection, 100 minerals, that you sent me yesterday, and it was an agreeable surprise. The beauty and size I never expected to of the specimens astonished ine. be in possession of any such collection, and I fear you are not well paid. If not I will send you more money, for I would not take twice what it cost me. I express my great obligations to you with thanks, until better paid. Yours very respectfully, A. JAGGER. A large number of postal card inquiries for Catalogue receive no notice, as I suppose them to come from school children who wish to gratify a little idle curiosity. It is sent only on recipt of price which is below cost, except to Museums and heads of Natural History or Chemical departments, in colleges applying for it on their official paper. Sample copy of the LEISURE HOUR sent free to any one. To insure a prompt reply postage should always be enclosed. It is a small matter to you, but our postage bills amount to between $200 and $300 each month. The kindness of scientific men everywhere has been acknowledged, but credit must be given to Prof Dana, Eggleston and Brush for the free use that has been made of their works on Mineralogy in preparing the lists tables and various articles in the Catalogue. Competent assistants supplied to private collectors who wish to visit interesting localities. In most cases payment for services can be made in specimens. Colfections named and arranged at very low rates. Shipping Directions. THERE are three (3) principal lines of Express to Philadelphia, viz. Ist, Phila and Reading R. R. and Delaware, Lackawana and Western, which control several thousand miles of road, 2d, Baltimore and Ohio and N Y. and Phila. New Line and New Eng. States, consolidated; and 3d, Adams. The American, United States and other companys deliver to one of these companies the same as to the other. Parties living at towns where there is no line but Adams, will, of course, have to send by it, but parties living at places where there is any other line are requested to ship by the other line, mark via N. Y. and N. E. or P. and R. and B. and O., or D., L. and W. Express as they may find will be the cheapest, but not by Adams. No packages sent by Adams, unless requested in the order for goods The Following rules, which are those of the largest dealers in Mathematical, Optical and Philosophical instruments in the United States, are those which we shall hereafter adopt : "The prices throughout the Catalogue will be strictly adhered to. "When no satisfactory Philadelphia or New York reference is given by the party ordering the goods, or if the order is less than $5, the money should accompany the order; but where it does not (either for want of confidence or other canse) the goods will be forwarded by express, with bill, C. O. D. (collect on delivery), provided a remittance equal to one-fifth of the total amount of the order is sent with it. "The Express Company's charge for collecting and returning the mony on C O. D. bills must be paid by the party ordering the goods. The safest and most economical method of remitting money is by Bank Draft. Check or Post Office Where neither of these Order, made payable to me. can be procured, United States or National Bank Notes or Postage Stamps, can be sent by express, or by registered letter, with safety, the sender prepaying the express charges. Goods ordered to be sent by mail must be pre-paid, and the return postage included in the remittance. "All the packing-boxes will be charged for, and all goods will be packed with the utmost care, but no responsibility will be assumed by us for breakage, loss in carriage, or other damage, after a package leaves our premises, except upon special contract. Packing-boxes, with screw covers, not charged for if returned in good condition prepaid There is nothing that I strive to exercise more care about than packing and shipping. I put my best men at it, and unless accident and delay is very plainly my fault, I do not consider myself responsible. In all cases customers must pay freight and postage. CRYSTALLIZATION, Slightly altered and abriged from Dana's Manual of Mineralogy and Lithology. See 18636, $1.75 The attraction which produces crystals is one of the fundamental properties of matter. It is identical with the cohesion of ordinary solidification; for there are few cases outside of the kingdoms of life in which solidification takes place without some degree of crys tallization. Cohesive attraction is, in fact, the organiz ing or structure-making principle in organic nature; it produces specific forms for each species of matter, as life does for each living species. A bar of cast-iron is rough and hackly in surface, because of the angular crystalline grains which the iron assumed as solidification took place. A fragment of marble glistens in the sun, owing to the reflection of light from innumerable crystalline surfaces, every grain in the mass having its crystalline structure. When the cold of winter settles over the earth in the higher temperate and colder latitudes it the signal for crystallization over all out-door nature; the air is filled with crystal flakes when it snows; the streams become coated with an aggegation of crystals called ice; and windows are covered with frost, because crystal has been added to crystal in long feathered lines over the glass-Jack Frost's work being the making of crystals. Water can not solidify without crystallization, and neither can iron nor lead, nor any mineral material, with perhaps a half dozen exceptions. Crystallization produces masses made of crystalline grains when it cannot make distinct crystals. Granite mountains are mountains of crystals, each particle being crystalline in nature and structure. The lava current, as it cools, becomes a mass of crystalline grains. In fact the earth may be said to have crystal foundations; and if there is not the beauty of external form, there is everywhere the interior profounder beauty of universal law-the same law of symmetry which, when external circumstances permit, lead to the perfect crystal with regular facets and angles. Crystals are alone in making known the fact that this law of symmetry is one of the laws of cohesive attraction, and that under it this attraction not only brings the particles of matter into forms of mathematical symmetry, but often developes scores of brilliant facets over their surface with mathematical exactness of angle, and the simplest of numerical relations in their positions. Crystals teach also the more wonderful fact that the same species of matter may receive,under the action of this attraction, through some yet incomprehensible changes in its condition, a great diversity of forms from the solid of half a dozen planes to one of scores. At the time of crystallization the material is usually in a state of fusion, or of gas or vapor, or of solution, In the case of iron the crystallization takes place from a state of fusion, and while the result is ordinarily a mass of crystalline grains, distinct crystals are sometimes formed in any cavities. If, in the cooling of a crucible of melted lead, bismuth, or sulphur, the crust be broken soon after it forms, and the liquid part within be turned out, crystals will be found covering the interior. Here also is crystallization from a state of fusion. When frost or snow flakes form, it exemplifies crystallization from a state of vapor. If a saturated solution of alum, made with hot water, be left to cool, crystals of alum after awhile will appear, and will become of large size if there is enough of the solution. A solution of common salt, or of sugar, affords crystals in the same way. Again, whenever a mineral is produced through the change or decomposition of another, and at the same time assumes the solid state. it takes at once a crystalline structure, if it does not also develope crystals. Further, the crystalline texture of a solid mass may often be changed without fusion; e. g., in tempering steel the bar is changed from coarse-grained steel to fine-grained by heating and then cooling it suddenly in cold water, and vice versa, and this is a change in every grain throughout the bar. Thus the various processes of solidification are processes of crystallization, and the most universal of all facts about minerals is that they are crystalline in texture. A few exceptions have been alluded to, and one example of these is the mineral opal, in which even the microscope detects no evidence of a crystalline condition, except sometimes in minute portions supposed not to be opal. But if we exclude coals and resins this mineral stands almost alone. Such facts, therefore, do not affect the conclusion that a knowledge of crystallography is of the highest importance to the mineralogist. It is important because, 1. A study of the crystalline forms and structures of minerals is a convenient means of distinguishing spe cies-the crystals of a species being essentially constant in structure and in angles. 2. The most important optical characters depend on the crystallization, and have to be learned from crystals. 3. The profoundest chemical relations of minerals are often exhibited in the relations of their crystalline forms. 4. Crystallization opens to us nature at her foundation work, and illustrates its mathematical character. The forms of crystals are exceedingly various, while the systems of crystallization, based on their mathe matical distinctions, are only six in number. Some of the simplest of the forms under these six systems are views represented in the following eight figures, and by a study of these forms the distinctions of the six systems will become apparent. |