CHAPTER IX

FOR MERCHANTS AND MANUFACTURERS OF LEATHER AND LEATHER GOODS The purpose of the department of the Guide in which this chapter appears, addressed to persons engaged in certain important occupations, is not only to show them how Britannica-reading will enlarge their knowledge of some aspects and relations of their business, but also to show how Britannica-reading will help them to realize the importance of _educating the general public_ in regard to that business. This education of the public is not necessarily confined to advertising, although the best form of advertising that can be used by anyone who sells a good article, or an article that is good at its price, is probably to tell the public what it really is and how it is really made. In the direct personal intercourse between salesman and purchaser there is opportunity for the imparting of information which, if it possesses genuine interest, will be gladly received and will stimulate trade. Mere praise of an article is uninteresting and unconvincing; while facts that explain _why_ that article is adapted to a particular use, and _why_ it is better than another article sold at a lower price will always receive attention. [Sidenote: About Selling Leather Goods] All this is especially true of leather goods, for the public ignorance on the subject of leather is abysmal. Nothing is more universally used, yet ninety-nine out of a hundred who use it not only do not know what lies beneath the surface of it, but do not know that there is any difference in value between a natural grain surface and a mechanically grained false surface, and it is quite certain that nearly all the men and women who walk out of a store after buying skiver would be nonplussed if they were asked whether the upper or lower part of a split skin was the best. Both the leather merchant and the public would be delighted to hear some of the curious things that the Britannica tells about leather, which is, from any point of view, one of the most interesting of all commodities; although few of those who use it, and perhaps as few of those who deal in it, ever stop to think how curious a relation there is between the original nature of the material and the qualities of the finished product. In cattle and sheep, the hide is a garment that covers every part of the body but the feet. Adapted to our own use, its most important service as a garment is to cover our feet. It is so far a natural product that no imitation of it possesses any of its chief merits, and yet so far an artificial product that when the hide has been removed from an animal, it requires treatment in order that it may not lose the flexibility which makes it, for a thousand purposes, more valuable than wood or metal, and in order that it may not decay. [Sidenote: What Skin Is] Skin is waterproof because its surface consists of scales, and although in most quadrupeds, as in man, these scales are so small as to be invisible, they will so resist the entrance of any tan liquor or other preservative fluid that they must be scraped away before the skin can be treated. Under these horny scales there is a layer of soft cells, and under this a membrane which makes the natural grain surface of leather. Under this, again, lies the “true” skin, in In the upper of these two, the white fibres lie parallel with the grain. In the lower, the white fibres, which are here coarser, lie in bundles, bound together by yellow fibres, so that this layer is really a woven fabric. The spaces in the weave are filled with a soft jelly, and the fibres do not multiply among themselves, as cells do, but are developed, as they are needed, from this jelly. Tan liquor has the peculiar property of converting this jelly into a “leathery” substance, which although it does not then assume the shape of fibres, becomes nearly as tough as the fibres themselves, and thus makes leather more solid and stronger than the original skin; and the virtue of leather depends largely on the presence of this jelly. [Sidenote: Naturally Woven Fibres] two layers. The body of an old bull will have absorbed it, just as fat is absorbed in old age, so that the spaces in the weave of the fibre are left vacant, and (as the scaly outer surface of the skin has been scraped away to admit the tan liquor) any water with which the hide comes into contact will be soaked up. That is why old bull leather is not waterproof and is lacking in substance. Again, the weave of this innermost layer of skin, lying next to the flesh, varies in different animals. In sheepskin the fibres are very loosely woven, and for this reason great care is needed in preparing the leather, and when the skin is split, the under half is only fit for the light usage to which “chamois” leather is restricted. But however the quality, surface or thickness of the skin may differ, its true structure is the same in all animals used for leather, save the horse, which is exceptional in possessing, over the loins, a third skin, very closely woven and very greasy, which makes horsehide taken from this part of the body peculiarly waterproof, pliable and durable. As you are in the leather business, you probably knew all these facts already, but perhaps they were not arranged in your mind in a form in which you could explain them to others as clearly as you will be able to do after reading the articles in the Britannica from which this general statement is summarized. And when you are reading about any other business, or about any other subject of any kind, you will find that the Britannica _goes to the root of the subject_ in the same thorough way in which it deals with the fibres and the jelly that make up the substance of leather. Now for the articles in detail—or the principal ones; the others are sufficiently indicated by the list at the end of this chapter. SKIN (Vol. 25, p. 188), by Dr. F. G. Parsons, vice-president of the Anatomical Society of Great Britain and Ireland, with illustrations from microscopic enlargements, covers the comparative anatomy of the skin in all groups of animals, and the process of skin development in the embryo. The articles mentioned in the chapter _For Stock-Raisers_ tell you about the domestic animals whose hides are chiefly used for leather. The chapter on _Zoology_ in this Guide gives a list of the articles on the other animals whose skins are tanned for fancy leathers. The main article LEATHER (Vol. 16, p. 330), equivalent to 50 pages of this Guide, is by Dr. James G. Parker, principal of the Leathersellers’ Technical College, London, and author of _Principles of Tanning_ and other standard trade text-books. After explaining the distinctions between tanned, tawed, and chamoised leathers, it takes up the subject of sources and qualities of hides and skins, and describes the structure of skin in relation to the finished product. The characteristics and peculiarities of hides and skins from different parts of the world are thoroughly explained. We learn why hides from animals bred in mountainous districts are the best, and where the finest sheep- and goat-skins come from. [Sidenote: Processes of Tanning] _Tanning Materials_ is the subject of the next section. These are classified into pyrogallols, catechols, and subsidiary materials; and the article describes their composition and preparation by grinding, with explicit directions for their testing, including the latest official method of the International Association of Leather Trades Chemists. The processes of making heavy leathers are next discussed. We learn the many ways of cleaning, softening, depilating, and fellmongering (or dewooling) by liming, rounding and scudding, and finally the process of actual tanning in its three steps of colouring, handling, and laying away. In connection with depilation, it is interesting to note that it has been discovered that it is not the lime but the action of bacteria in the lime which causes the hair to fall out. The finishing of sole leather, harness leather and other grades is explained, also the theory of the formation of the “bloom” and its removal, as well as the process of “scouring.” The art of _Currying_ has a section to itself, and the preparations for tanning or dressing hides for trunks and suit cases by bating, puering, scudding, plumping, drenching and splitting, receive detailed attention. The tanning of light leathers, and all the varieties of basils, skivers, Russia leather, seal, alligator, snake, frog and kangaroo leathers, Japan and enamel leathers are fully treated. _Tawing_, _Wooling_, _Dressing_, _Chrome Tanning_, _Combination Tannages_, _Oil Tanning_ (Chamoising), _Preller’s Helvetia_ or _Crown Leather_, _Transparent Leather_, _Parchment_, _Tar and Peat Tanning_, _Dyeing_, _Staining_ and _Finishing_, _Glove Leathers_, and _Bookbinding Leathers_ are some of the other sections of this excellent treatise. LEATHER, ARTIFICIAL (Vol. 16, p. 345) is a separate article. [Sidenote: Chemistry of Leather Manufacture] TANNIN, or TANNIC ACID (Vol. 26, p. 399) is a general account of the vegetable products which have the property of converting raw hide into leather. Specific information about the materials from which the pyrogallol tannins are obtained will be found under MYROBALANS (Vol. 19, p. 114), CHESTNUT (Vol. 6, p. 112), DIVIDIVI (Vol. 8, p. 332), SUMACH (Vol. 26, p. 70), OAK (Vol. 19, p. 931), GALLS (Vol. 11, p. 422) a full and interesting account of the insect produced vegetable excrescence which yields a high percentage of tannin, by Francis H. Butler, of the Royal School of Mines; and WILLOW (Vol. 28, p. 688). For the catechol tannins see HEMLOCK (Vol. 13, p. 262), CATECHU (Vol. 5, p. 507), MANGROVE (Vol. 17, p. 572), MIMOSA (Vol. 18, p. 500), LARCH (Vol. 16, p. 211), BIRCH (Vol. 3, p. 958), which yields the empyreumatic oil used in the preparation of Russia leather, to which the pleasant odor is due. There are numerous articles in the Britannica on the chemicals used in the process of tawing, chrome tanning, etc., such as ALUM (Vol. 1, p. 766), ACETIC ACID (Vol. 1, p. 135), GLAUBER’S SALT (Vol. 12, p. 114), BICHROMATES AND CHROMATES (Vol. 3, p. 912). [Sidenote: Dyeing] The chief classes of dyes used for leather are the acid; basic, or tannic; direct, or cotton; and mordant dyes, and these are described at great length in a valuable article DYEING (Vol. 8, p. 744), equivalent to 20 pages of this Guide, by the late J. J. Hummel, professor of Dyeing, University of Leeds, and Dr. Edmund Knecht, professor of Technological Chemistry, University of Manchester. The section on the _Theory of Dyeing_ shows how the dyeing property of a substance depends upon its chemical composition. Separate articles go more deeply into the chemistry of dyeing materials used with leather, and some of the more important of these are SULPHONIC ACIDS (Vol. 26, p. 60), SULPHURIC ACID (Vol. 26, p. 65), FORMIC ACID (Vol. 10, p. 668), ANTIMONY (Vol. 2, p. 127), TITANIUM (Vol. 26, p. 1017), IRON (Vol. 14, p. 796), LOGWOOD (Vol. 16, p. 922), FUSTIC (Vol. 11, p. 375), BRAZIL WOOD (Vol. 4, p. 463), and TUMERIC (Vol. 27, p. 474). Comparatively few of the coal-tar colours have as yet been adapted to leather manufacture, but their characteristics are discussed in such articles as AZO-COMPOUNDS (Vol. 3, p. 81), ANILINE (Vol. 2, p. 47), INDULINES (Vol. 14, p. 507), FUCHSINE (Vol. 11, p. 273), and SAFRANINE (Vol. 23, p. 1000). [Sidenote: Special Leathers] PARCHMENT (Vol. 20, p. 798), by Sir E. Maunde Thompson, Principal Librarian, British Museum, is an interesting historical account of the skins and their preparation. Their use as writing material was widespread at a very early period. “The Jews made use of them,” says the article “for their sacred books, and it may be presumed for other literature also; and the old tradition has been maintained down to our own day, requiring the Synagogue rolls to be inscribed on this time-honoured material.” The difference between parchment and vellum is explained. SHAGREEN (Vol. 24, p. 769) tells about a species of untanned leather used for ornamental purposes. It is a curious fact that the addition of the word “chagrin,” for anxiety or annoyance, to the English language was due to the unpleasant sensation that came from touching the rasping surface of this leather. Stamped leather for wall hangings is described in the section _Stamped Leather_ of the article MURAL DECORATION (Vol. 19, p. 19), by William Morris and Walter Crane. SHOE (Vol. 24, p. 992) contains an illustrated section on the _Manufacture of Leather Shoes_. SADDLERY AND HARNESS (Vol. 23, p. 988), by Cecil Weatherly, and GLOVE (Vol. 12, p. 135) are treated both from an historical and a practical point of view. BOOKBINDING (Vol. 4, p. 216), illustrated, by C. J. H. Davenport, of the British Museum, has a great deal of interesting information about the leathers used in this art. The flexible binding, which has been applied for the first time on a large scale in the new Britannica, originated when vellum instead of paper was used for books, and it possesses the great advantage that a volume sewed in this way can be opened flat, and lies flat without being held. ALPHABETICAL LIST OF ARTICLES AND OF SUBJECTS IN THE ENCYCLOPAEDIA BRITANNICA OF SPECIAL INTEREST TO THOSE IN THE MANUFACTURE AND SALE OF LEATHER AND LEATHER GOODS Acetic Acid Acid dyes Aldehyde tanning Algarobilla Alligator Leather Alum Angols Aniline Antimony Azo Compounds Barkometer Basic, or Tannin dyes Basils Bates Bating Bichromates and Chromates Birch Bleaching Bloom Bookbinding Bookbinding Leathers Bottle-tanning Brazil Wood Canaigre Catechols Catechu Chamoising Chestnut Chestnut Oak Chrome Box Chrome Tanning Colouring Pits, or Suspenders Combination Tannages Crust Stock Currying Apparatus Currying Processes Dash-wheel Depilation Direct, or Cotton, Dyes Dividivi Dongola Leather Drenching Dressing Drum Dyeing Dusting Material Dyeing Enamel Leather Erodin Fatliquoring Fellmongering, or Dewooling Finishing Formic Acid Frog Skin Fuchsine Fustic Galls Gambier Glauber’s Salt Glazing (Glacé leather) Glove Glove Leathers Grinding Machinery and Leaching Handlers, or Floaters Heavy Leathers Hemlock Hide Mill, or Double-Acting Stocks Hide-powders Hides and Skins Indulines Iron Iron Tannage Janus Colours Japan Leather Kangaroo Leather Kaspine Leather Kips Larch Leather Leather, Artificial Levant Morocco Liming Logwood Mangrove Mimosa, or Golden Wattle Mordant dyes Morocco Leather Myrobalans Oak bark Oak wood Oil Tanning Parchment Payne and Pullman Process Peat Tanning Pigskin Portmanteau Power Transmission, _Belts_ Preller’s Helvetia or Crown Leather Puering Pyrogallols Quebracho Roans Russia Leather Saddlery and Harness Safranine Sammying Scudding Seal Leathers Setting Shagreen Shoe Skin Skivers Snakeskin Splitting Machines Staining Sulphonic Acids Sulphuric Acid Sumach Sweating Tan Liquors Tanner’s Beam Tanner’s Hook Tanner’s Knives Tannin, or Tannic Acid Tawing Tiffany Bate Titanium Transparent Leather Tray Dyeing Turmeric Upper Leather Valonia Vellum Vidal Colours Waxing Willow Willow Calf Tannin Precipitation Tanning Materials Tar Tanning Wilson Scouring Machine Wool-rug Dressing