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.
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.
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. |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.
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.