,transcriber's note3 ,spelling and punctuation inconsistencies been harmonized4 ,obvious printer errors have been repaired4 ,italic text has been marked with underscores4 ,bold text has been marked with equal signs4 ,subscript numbers have been rendered1 as for example for subscript #b1 as #b4 ,,leather ,common ,commodities and ,industries ,series ,each book in crown #hvo1 cloth1 with many illustrations1 charts1 etc4 #bs4 #f;d4 net4 ,tea3 ,from ,grower to ,consumer4 ,by ,a4 ,ibbetson4 ,coffee3 ,from ,grower to ,consumer4 ,by ,b4 ,b4 ,keable4 ,sugar3 ,cane and ,beet4 ,by ,geo4 ,martineau1 ,c4,b4 ,cotton3 ,from the ,raw ,material to the ,finished ,product4 ,by ,r4 ,j4 ,peake4 ,rubber3 ,production and ,utilisation of the ,raw ,product4 ,by ,c4 ,beadle and ,h4 ,p4 ,stevens1 ,m4,a41 ,ph4,d41 ,f4,i4,c4 ,iron and ,steel3 ,their ,production and ,manufacture4 ,by ,c4 ,hood4 ,silk3 ,its ,production and ,manufacture4 ,by ,luther ,hooper4 ,tobacco3 ,from ,grower to ,smoker4 ,by ,a4 ,e4 ,tanner4 ,wool3 ,from the ,raw ,material to the ,finished ,product4 ,by ,j4 ,a4 ,hunter4 ,coal3 ,its ,origin1 ,method of ,working1 and ,preparation for the ,market4 ,by ,francis ,h4 ,wilson1 ,m4 ,inst4 ,m4,e4 ,linen3 ,from the ,field to the ,finished ,product4 ,by ,alfred ,s4 ,moore4 ,timber3 ,from the ,forest to its ,use in ,commerce4 ,by ,william ,bullock4 ,clays and ,clay ,products4 ,by ,a4 ,b4 ,searle4 ,leather3 ,from the ,raw ,material to the ,finished ,product4 ,by ,k4 ,j4 ,adcock4 ,oils3 ,animal1 ,vegetable1 ,essential1 and ,mineral4 ,by ,c4 ,ainsworth ,mitchell1 ,b4,a41 ,f4,i4,c4 ,wheat and its ,products4 ,by ,a4 ,millar4 ,copper3 ,from the ,ore to the ,metal4 ,by ,h4 ,k4 ,picard1 ,assoc4 ,royal ,school of ,mines1 ,mem4 ,inst4 of ,min4 and ,met4 ,paper3 ,its ,history1 ,sources1 and ,production4 ,by ,h4 ,a4 ,maddox4 ,glass and ,glass ,manufacture4 ,by ,percival ,marson4 ,soap3 ,its ,composition1 ,manufacture1 and ,properties4 ,by ,william ,h4 ,simmons4 ,the ,motor ,industry4 ,by ,horace ,wyatt1 ,b4,a4 ,the ,boot and ,shoe ,industry4 ,by ,j4 ,s4 ,harding4 ,gums and ,resins4 ,by ,ernest ,j4 ,parry4 ,furniture4 ,by ,h4 ,e4 ,binstead4 ,other ,volumes in preparation4 ,illustration3 ,,bleaching ,,oil-,,tanned ,,leather ,,by ,,exposure ,,to ,,the ,,sun ,the ,rosary ,leather ,mills4 ,ashtead ,,pitman',s ,,common ,,commodities ,,and ,,industries ,,leather ,,from ,,the ,,raw ,,material ,,to ,,the ,,finished ,,product ,,by ,k4 ,j4 ,,adcock ,,london ,,sir ,,isaac ,,pitman ,,sons1 ,,ltd41 #a ,,amen ,,corner1 ,e4,c4#d ,,bath1 ,,melbourne ,,and ,,new ,,york ,,printed ,,by ,,sir ,,isaac ,,pitman ,,sons1 ,,ltd41 ,,london1 ,,bath1 ,,melbourne ,,and ,,new ,,york ,,contents ,,chap4 ,,page ,i4 ,,evolution ,,of ,,leather ,,manufacture #a ,,ii4 ,,hides ,,and ,,skins #e ,,iii4 ,,tanning ,,materials #cb ,,iv4 ,,machinery #eb ,v4 ,,preparation ,,of ,,hides ,,and ,,skins ,,for ,,tanning #fb ,,vi4 ,,tanning ,,processes #ia ,,vii4 ,,dressing1 ,,dyeing1 ,,and ,,finishing ,,of ,,leather #aab ,,index #aei ,,list ,,of ,,illustrations ,,page ,,bleaching ,,oil-,,tanned ,,leather ,frontispiece ,,mechanical ,,flaying #bc ,,pim',s ,,system ,,of ,,flaying #bd ,,warble ,,fly #bh ,,warbled ,,kip 7#ehd ,,holes7 #bi ,,warbled ,,hide 7,,magnified7 #cj ,,tanning ,,extract ,,plant #dh ,,shaving ,,cylinder #ec ,,bladed ,,cylinder ,,for ,,buffing #ed ,,band-,,knife ,,splitting ,,machine #ed ,,shaving ,,knife #ee ,,shaving ,,machine bet4 pp4 #ef #eg ,,shaving1 ,,old ,,method #ef ,,shaving ,,machine1 ,,knife ,,guard #ei ,,shaving ,,machine #fa ,,drum ,,tumbler #fg ,,faller ,,stocks #fg ,,tanner',s ,,beam #fh ,,lime ,,yard #gc ,,dehairing ,,knife #hj ,,dehairing ,,and ,,fleshing ,,machine #ha ,,fleshing ,,knife #hc ,,scudding ,,knife #hf ,,bark ,,mill #ic ,,tan-,,yard #id ,,rounding ,,of ,,hides #ie ,,barkometer #ig ,,paddle ,,vat #ajc ,,pinning ,,sole ,,butts #aba ,,rolling ,,machine #abb ,,rolling ,,sole ,,leather #abc ,,fan ,,for ,,drying #abd ,,fan ,,fixed ,,in ,,chamber #abe ,,sutcliffe ,,system ,,of ,,drying #abf ,,sleeker #abh ,,fluffing ,,machine #abi ,,striking-,,out ,,and ,,scouring ,,machine #acj ,,leather-,,stuffing ,,drum #ace ,,staking ,,and ,,glazing ,,machine #adc ,,leather ,,chapter ,i ,,evolution ,,of ,,the ,,art ,,of ,,leather ,,manufacture ,before describing the making of leather by up-to-date methods1 it may be useful to attempt to outline the evolution of the ancient art of tanning and dyeing skins4 ,as everyone knows1 leather is the preserved skin of various animals1 but the origin of the conversion of raw skins into an imputrescible material will probably never be traced1 and it can only be assumed that the processes necessary to produce leather from skins were gradually and1 in most cases1 accidentally discovered4 ,long before the ,christian era1 the ancient ,egyptians had succeeded in bringing the manufacture of leather to remarkable perfection1 and1 had they at their service the wonderful machinery now available to the leather industry1 it is certain that their productions would have lost little or nothing by comparison with modern leather4 ,happily1 specimens of ancient ,egyptian leather have been preserved in one national museum1 and1 although they are said to have been made at least #c1jjj years ago1 the colour and natural strength of the leather are unimpaired4 ,judging by the advanced state of the art of leather manufacture in the early ,egyptian period1 it is obvious that the origin of its manufacture must have considerably antedated that period1 and1 indeed1 it would be necessary to go back almost to the creation of man to find the origin of the use of preserved animal skins for clothing4 ,the primitive method would naturally consist of simply drying the skin1 in which condition it would keep for many years unless it came into contact with moisture1 though its horniness would no doubt cause the wearer much discomfort4 ,it must not be supposed that the wearing of dried raw skins with the hair left on was impracticable1 for even to-day some of the skins of fur-bearing animals used for personal adornment are cured in this primitive way1 with the additional treatment with napthalene for disinfecting purposes and keeping away injurious insects and moths1 the object of the limited amount of dressing being to preserve the natural strength and coloration of the fur4 ,in such a condition1 however1 the skins are liable to acquire an unpleasant odour1 and for hygienic reasons it is advisable that all skins in the hair used for clothing or rugs should be properly dressed1 so that no decay sets in to loosen the hair or fur4 ,even now1 the process of simply drying hides and skins to preserve them before sending them to the tanner is largely practised1 especially in hot climates and in those countries where salt is not readily available4 ,this process of curing rests on the chemical theory of dehydration1 which1 in a modified form1 has recently been successfully applied to some experiments in making leather4 ,finding that the simple drying of skins would not properly prepare them for clothing1 primeval man would naturally look for some means of treating them to conserve their original softness and pliability1 and the nearest substances at hand would be animal fats and brains4 ,it is almost safe to assume that this process was the first by which hides were preserved in a state differing from their original condition1 the oxidation of the fatty matters naturally producing a partial tannage4 ,the effect of smoke may also have been discovered in the earliest days of skin-curing1 and it is reported that even now one or two tribes use smoke to preserve skins4 ,the somewhat imperfect preservation of the hides by this method would lead to further experiments being made1 which evidently resulted in the discovery of the tanning effect of leaves1 twigs1 and barks of trees when soaked in water4 ,it may be that the preservative effect of alum was discovered even before the vegetable tanning process1 for the original ,japanese white leather was made simply by steeping the raw hides in certain rivers which contained a bed-rock of alum4 ,this primitive process is even followed to-day in one or two places in ,japan1 but the leather is afterwards treated with oil to impart tensile strength and increased suppleness4 ,strictly speaking1 these hides are not leather when finished1 and they are quite unsuitable for boots2 but1 being the toughest material known in the leather trade1 with the possible exception of raw hide1 it is particularly suitable and chiefly used for brace ends1 and occasionally for ladies' belts4 ,it must not be inferred from reference to this process that the ,japanese only use this earliest method of making leather2 on the contrary1 they are producing all classes of leather1 and especially belting and sole1 by modern ,european methods1 and it may not be long before their competition with ,american and ,european productions becomes an accomplished fact4 ,the available information seems to show that1 until about thirty years ago1 the development of the industry was mainly the result of accidental discoveries1 and that the theory of tanning and leather-dressing was imperfectly understood until within quite recent times4 ,records of the leather trade #cjj years ago prove that the methods then in vogue were of the rudest kind2 further1 they show that the practice of skimping the tanning process was not unknown in those days1 for a contemporaneous author describes the horny condition of some of the leather which1 despite the ,government inspection1 appeared to have passed into the old ,leadenhall market for sale by the simple operation of greasing the fist of the seller4 ,spain and ,hungary had by that time established the manufacture of morocco and curried leather on a fairly sound basis1 while a few years later ,france began to develop the industry of leather manufacture4 ,until about twenty years ago1 waxed calf1 crup1 calf kid1 and alum-tanned kid were staple upper leathers1 together with the old ,spanish cordovan leather4 ,the sole leather used in ,england was chiefly the output of tanneries in the ,united ,kingdom4 ,about twenty years ago1 however1 the successful application of the chrome tanning process caused quite a revolution in the leather trade1 with the result that about nine-tenths of the world's production of boot upper leather is chrome-tanned4 ,the introduction of this process on a practical scale gave a great impetus to the work of chemists1 who have since made some remarkable discoveries and have placed the art of leather manufacture on a scientific basis4 ,the old methods1 however1 are by no means obsolete1 and it is somewhat remarkable to find that a ,british patent was taken out last year 7#aiad7 for converting hides and skins into leather by treating them with brains and smoke4 ,,chapter ,,ii ,,hides ,,and ,,skins ,the hides and skins of animals form the principal raw material of the tanner4 ,technically1 the term hides is applied to the skins of the larger animals1 while the word skins is used in the case of the smaller animals4 ,thus1 the tanner speaks of ox1 cow1 bull and horse hides1 and of calf1 sheep1 and goat skins4 ,there is an intermediate size between a full-grown calf skin and a small hide1 and this is known as a kip1 but the line of demarcation is not very clear4 ,buyers often settle the difficulty by examining the growth marks and the irregular substance of the skin1 and1 if these are marked features1 it is classified as a kip4 ,the condition of the hides of cattle is usually inferior during the six months after the animal has become a yearling4 ,east ,india tanned hides1 which are largely imported into ,england1 are frequently described as ,e4,i4 kips in the trade4 ,this is hardly accurate1 but the mistake is probably due to the small size of full-grown ,indian hides1 which are very little larger than the average ,european kips4 ,it is interesting to observe that furriers always refer to both their raw material and the finished product as skins1 irrespective of the size of the fur-bearing animals4 ,most of the skins of wild animals are dressed without removing the hair or fur1 and this is quite a distinct trade from leather manufacture1 the only exception being the dressing of closely cut and fine-haired calf skins for slippers and fancy articles4 ,practically every country in the world contributes to the supply of hides and skins1 but there are a few countries which are far in advance of the others in the industries of cattle and sheep-raising4 ,the sources of tanners' raw material have undergone great changes since the establishment of freezing and chilling stores for the preparation of meat for export1 and the market prices of hides are to a large extent controlled by the supply in ,north and ,south ,america1 ,south ,africa1 and ,australia4 ,whether or not the concentration of these huge meat works into two or three centres is likely to benefit the leather trade is a debatable point4 ,the flaying1 trimming1 and curing of hides in these establishments are certainly superior to the work done by the average butcher1 while1 owing to the large numbers of cattle slaughtered1 the hides can be closely selected4 ,on the other hand1 the value of hides and skins has risen enormously in the last decade1 the period coincident with the rapid growth of the chilled and frozen meat industry1 but the increased use of leather in many directions may be mainly responsible for the higher cost of the raw material1 although it is obvious that the concentration of the chief supplies of hides in a few lands must tend to increase the severity of the competition among buyers4 ,apart from the high prices of the hides1 the concentration of the meat industry in large chilling and freezing works has had the effect of increasing the prices of beef and mutton1 which are now higher in price than freshly-killed ,english meat was a few years ago4 ,it appears to have been a grave error on the part of the ,british ,government when they stopped the imports of live cattle owing to the fear of foot-and-mouth disease being communicated to domestic herds4 ,the disease has broken out in several places since the embargo was imposed1 so that the theory that the infection was only carried by imported live cattle has been clearly disproved4 ,the butchering of cattle provides a large amount of work in subsidiary industries1 and the ,government embargo on the importation of live cattle has caused a great deal of distress in ,deptford and ,birkenhead1 where large abattoirs were erected for the reception of live cattle1 which used to be imported in fairly large numbers4 ,there is no danger of foot-and-mouth disease getting beyond the abattoirs or of the slaughter of diseased cattle for food1 and both tanners and butchers hope to see the removal of the embargo4 ,so far as possible1 each country should raise its own cattle to provide its own meat supply1 and this principle is recognised by many countries which prohibit the import of foreign meat3 but1 owing to the rapid growth of populations in industrial countries1 with the consequent increase in the value of land1 it has become impracticable to raise enough cattle to supply domestic needs4 ,even the ,united ,states of ,america1 which formerly had a great cattle-raising industry1 has lately been obliged to import live cattle to meet the requirements of its inhabitants4 ,similar conditions prevail almost throughout ,europe1 and tanners have to look to ,south ,america1 ,australia1 and ,africa for large supplies of raw hides1 although there are still some tanners in the ,united ,kingdom who use only the hides produced in this country4 ,the bulk of the production of hides and skins in the ,united ,kingdom is disposed of at weekly public auctions in the principal towns3 ,london1 ,manchester1 ,liverpool1 ,leeds1 ,birmingham1 ,newcastle1 and ,glasgow being the largest centres of distribution4 ,however1 there is still a large quantity bought by private treaty1 and opinions are divided as to which is the better method of buying4 ,before the establishment of public auctions1 hides were very cheap1 but tanners were unable to get a good selection1 although1 for sole leather1 that was not a very important matter4 ,public auctions have become so firmly established that it would be impossible for tanners to revert to the old system even if they desired it4 ,the competition of private buyers with the auction markets has certainly benefited the butcher at the expense of the tanner1 and the weighing and classification of hides ultimately became so irregular in many markets that the ,tanners' ,federation of the ,united ,kingdom had to take strong action not long ago to protect their interests4 ,they demanded the appointment of an independent inspector at each market to check the weighing and sorting of the hides1 but this was successfully resisted by the market proprietors1 who eventually agreed to the tanners appointing travelling inspectors to visit the markets periodically4 ,the system is said to have improved matters4 ,the ,english markets do not collect enough hides to permit their close sorting1 so that1 while the hides are graded according to weight and quality and the sex of the animal1 the question of varying substances is generally ignored4 ,there is usually a difference of #aj lb4 in each class where the hides are sorted by weight ,ox1 cow1 heifer1 and bull hides are sold separately1 as each sort has a different value4 ,bull hides are comparatively poor in quality1 owing to their irregular substance and strong growth marks in the neck4 ,ox hides are the most suitable for sole leather and belting1 while cows' and heifers' are used mainly for dressing hides1 which are finished into bag1 case1 strap1 and boot leathers4 ,the hides known as ,scotch and ,hereford runts are the best of those produced in the ,united ,kingdom1 as they are well-grown1 compact1 and well-suited to the making of sole leather and belting4 ,the grading of the weight of these hides at the auction markets is generally as follows3 #ajj lb4 and above1 #ij-ii lb41 #hj-hi lb41 #gj-gi lb41 #fj-fi lb41 #ei lb4 and less4 ,this does not give an ideal classification1 as hides vary so much in texture and substance1 and it is quite possible to find spready hides of poor substance and quality which would be heavier than a small but compact and well-grown hide4 ,it would be better from the tanner's point of view if the hides were selected according to substance and quality4 ,there are not many bull hides grown in the ,united ,kingdom1 and in many markets they are not classed by weight but simply into best and secondary qualities4 ,horse hides are of even less value than those of bulls1 owing to their weaker texture and irregular substance4 ,that part of the skin under the mane is almost worthless1 while the flanks and sides are only useful for a secondary class of boot upper leather1 although some fairly good patent sides have lately been produced from horse hide1 which is suitable for that purpose owing to its soft grain and pliable texture when tanned4 ,the most valuable part of a horse hide is the butt1 which consists of the part known as the shell4 ,this shell is covered with an extremely fine grain which is not found in any other part of the hide4 ,the well-known crup leather is made from the shell of the horse hide4 ,in addition to hides1 there are fairly large quantities of calf and sheep skins sold at the weekly auctions1 but veal is not such an important article of food in ,england as it is on the ,continent4 ,sheep skins are far more numerous1 as ,great ,britain is a big mutton-consuming country4 ,home supplies of both hides and skins have been greatly reduced1 however1 by the immense import of frozen and chilled meat4 ,although the domestic supply of hides and skins is quite inadequate to meet the needs of ,british tanners1 a large proportion is exported4 ,american tanners buy large quantities of the best hides and pickled sheep skins4 ,the latter are dewoolled and preserved by a process of pickling with formic or sulphuric acid and salt before exportation4 ,those preliminary operations are the work of the fellmonger4 ,nearly all of the horse hides produced in the ,united ,kingdom are1 or were before the ,war1 sent to ,germany1 and ,british leather-dressers appear to have lost the art of finishing horse hide1 or are unable to convert it into leather profitably4 ,the interchange of raw hides between various countries1 and even between those where leather manufacture is an important industry1 is somewhat remarkable1 and only goes to prove that the concentration of a particular industry in one or two centres of the world gives these places a great advantage in regard to labour1 organisation1 and technical skill1 even over those countries where the raw material is plentiful4 ,theoretically and economically it should be advantageous to establish tanneries close to the supply of raw hides1 since the latter1 under present conditions of preservation1 steadily deteriorate from the time they are removed from the carcase until they reach the tannery4 ,in some countries the methods of preserving hides are actually so bad that the hides have often lost half of their value before the tanner gets them4 ,two or three of the largest ,american meat-packing establishments have erected or taken over tanneries to deal with raw hides1 one of their by-products4 ,tanneries have also been erected near some of the large meat works in the ,argentine1 but the development of the leather trade there is by no means rapid1 and at present the ,united ,states of ,america is the largest leather-producing country in the world4 ,germany1 ,france1 and the ,united ,kingdom come next in the order named4 ,south ,africa is an important source of supply of raw material1 and large quantities of ,cape hides are sent to ,england4 ,the production of raw hides there is likely to be on a very large scale in a few years' time1 as the raising of ,afrikander and other breeds of cattle is sure to become an important industry now that the ravages of the terrible disease1 known as tick1 have been checked4 ,china is another large hide-exporting country2 most of the hides from this source are dried in the open air and are generally arsenicated to prevent the ravages of insects4 ,immense quantities are also provided in all other populous countries1 but the demand for leather is generally greater than the production of raw material in those countries4 ,india is a noteworthy exception to this general rule2 the production of ,indian hides is enormous1 and1 although the leather trade is being developed1 there is a large surplus of raw hides and skins for export4 ,large quantities are roughly tanned1 however1 and exported to ,england1 ,germany1 ,france1 and other ,european countries to be dressed and finished4 ,the greater proportion of these hides and skins is used for the making of shoe leather1 while a good quantity is used for bag 7hide7 and imitation morocco 7goat7 leathers4 ,naturally1 there is in the aggregate a considerable supply of raw hides and skins from other parts of the world in addition to that from the countries specially named1 and new sources are being frequently found4 ,it would be impossible to describe the characteristics of the numerous varieties of hides and skins except in a full-sized text-book1 but a brief description of the principal sorts may be given4 ,some of the varieties produced in the ,united ,kingdom have already been described4 ,in the main1 there is not a great deal of difference in the hides of various breeds1 but there is a type of well-grown and stout hides specially suitable for sole and belting leather2 this class is known as runts1 and these hides are obtained from the ,scotch and ,hereford breeds of cattle4 ,the ,scotch runts from the ,highland cattle are more valuable than any other class of hide found in the ,united ,kingdom2 unfortunately1 the production is small4 ,irish cattle also yield good hides1 but in ,england the interests of the cattle owner1 or feeder1 are in conflict with those of the tanner1 for the system of artificially fattening cattle with oil cakes tends to make the hides very greasy and weaker in the fibres than those hides from animals which are reared on natural food-stuffs4 ,this grease is very difficult to remove and reduces the selling value of sole leather by about #b;d4 per lb4 ,the use of a borax solution for soaking partially removes the grease1 while it has been proposed that the pelts should be treated with a solution of hyposulphite of soda just before placing them in the tan liquors4 ,a drawback of the latter process is that a little weight is lost in the finished leather4 ,the trouble caused by the presence of a large quantity of natural grease is even more pronounced in sheep skins than in cattle hides4 ,naturally1 a sheep arrives at maturity in about two years2 but by the modern system of intensive feeding with oily food-stuffs it can be fattened in about ten months4 ,this is obviously a great advantage to the sheep-breeder2 in other respects it is an unsatisfactory method1 for the mutton is not so well matured1 and1 therefore1 is not so nourishing2 it contains too large a proportion of fat1 and the skins are very greasy and weak in fibre4 ,the excess of grease does not detract from the value of the wool1 and may even be beneficial4 ,there are several varieties of sheep in the ,united ,kingdom1 with widely different characteristics4 ,a fellmonger should have a good knowledge of the skins of various breeds in order to buy the particular sorts that will meet the requirements of his customers1 as his business is to separate the wool from the skins and to supply the former to the woollen factories and the latter to the leather-dressers4 ,he has1 therefore1 to study carefully both the wool and pelt markets4 ,while some breeds of sheep yield fine long wool of bright lustre1 others have comparatively short-stapled1 and kempy wool4 ,between these two classes1 there are numerous grades1 and the task of sorting the various qualities of wool in those fellmongeries where several classes of skins are worked is by no means easy4 ,it is a generally accepted axiom that the pelt 7i4e41 the skin denuded of wool7 is weaker in fibre in those skins which yield the finest and best wool4 ,in support of this1 the ,welsh mountain sheep may be cited4 ,this sheep has short1 curly wool1 but its skin is tough and strong on the grain4 ,in fact1 it is about the only breed suitable for roller leather1 which is used in the cotton industry for covering the drawing rollers of spinning-machines4 ,most of this leather is made in ,north ,wales1 whence it is exported to every country where the cotton industry is carried on4 ,notable exceptions of the general rule regarding the relative qualities of wool and pelts are found in two or three ,english varieties1 namely3 the ,lincolns1 ,leicesters and black-faced ,suffolks1 which produce both fine wool and large pelts of good quality4 ,other useful ,british breeds are the ,southdowns1 ,devons1 ,shropshires1 ,wensleydales1 ,scotch black-faced1 ,cotswolds1 and ,kerrys4 ,of the imported varieties1 the ,new ,zealand and ,cape sheep skins are the best4 ,the former1 principally merino stock1 not only provide very fine wool1 but also pelts of choice quality and large pattern4 ,although the quality of the wool of ,australian merino sheep is little1 if any1 inferior to that of the ,new ,zealand type1 the skins are not so good in quality1 due1 no doubt1 to the hotter climate1 which is favourable to the breeding of insects and other pests which damage the skins4 ,the ,cape sheep provide a skin which is quite different in texture from that of any other breed4 ,it has a certain looseness of texture and softness of grain which make it particularly suitable for the manufacture of glove leather4 ,south ,america is another large sheep-breeding country2 but the skins of this variety are not largely imported into ,england1 most of them being sent to ,mazamet1 the great centre of the fellmongering industry in ,france4 ,buenos ,aires skins are the most favoured of the ,south ,american skins1 owing to their large size and good substance4 ,monte ,videos are also very fine skins4 ,smyrnas and ,bagdads are other well-known varieties1 but they are generally imported in a rough-tanned condition1 or1 as it is known technically1 in the crust4 ,leather-dressers finish them for various purposes1 but mainly for boot and shoe lining leather4 ,when properly tanned by the natives1 these skins produce a supple finish1 especially those of the ,smyrna variety4 ,unfortunately1 many lots are merely coloured on the surface with the tan liquor1 with the result that they dry hard and tinny2 such partially-tanned leather is very difficult to finish and is rarely satisfactory4 ,even when the tannage is completed elsewhere before finishing them1 they never produce such good leather as skins properly tanned in the first instance4 ,russia is another important country for the production of all kinds of raw hides and skins suitable for leather manufacture4 ,american tanners buy very largely from this market1 and a few enterprising firms even send their own representatives to the great annual fair held at ,nishni ,novgorod1 where large quantities of dried hides and skins1 besides many other kinds of produce1 are offered for sale4 ,british tanners take comparatively little interest in this important supply1 but1 as a result of the great ,european ,war1 an increase of trade between ,russia and the ,united ,kingdom is anticipated1 although the ,russian leather trade is developing rapidly and will absorb increasing quantities of native raw material4 ,excepting a few in ,ireland1 raw goat skins are not produced in ,great ,britain4 ,the chief drawback to goat breeding there is a somewhat inexplicable aversion on the part of the public to the flesh of goats2 although another reason may be the destructive nature of the animals themselves1 for they devour and uproot anything edible that comes in their way4 ,it is1 perhaps1 unfortunate that some of the large areas of uncultivated land in ,great ,britain are not given up to the breeding of goats on a large scale1 since these hardy animals will thrive on rough1 hilly lands4 ,apart from the value of the meat1 it might be a paying proposition to rear large herds of goats for the supply of milk 7which is more nourishing than cows'7 and skins4 ,leather-dressers are1 therefore1 dependent on imported supplies1 of which the principal sources are ,india 7,north-,western ,district71 ,mexico1 ,arabia1 ,africa1 ,south ,america1 and several ,european countries4 ,goat skins from the main sources of supply vary very much in quality--even those produced in the same country4 ,in ,india1 for example1 skins may be obtained in some districts which can be made into leather to sell at about #e;d4 per square foot2 from another district1 when finished into the same kind of leather1 say glazed kid1 they may be worth #as4 #d;d4#a per foot4 ,fineness and clearness of grain and good substance are the main essentials of a first-class goat-skin leather2 unfortunately these qualities are rarely combined in one class of skin1 and there is a decided surplus of light thin skins which are hardly saleable1 even for ladies' shoes4 ,some ,american shoemakers overcome this difficulty by pasting a piece of cloth on the back of the skin4 ,in fairness to the buyer1 the boots made of such leather should be specially marked1 as the wearing quality of a backed thin leather is not to be compared with one naturally stout4 #a ,it must be understood that1 owing to the war1 these prices have been greatly increased4 ,the skins of goats are used for many purposes besides the manufacture of the famous glac kid leather2 gloves1 moroccos for bookbinding1 upholstery for furniture1 fancy articles such as purses1 pocket-books1 bags1 and ladies' belts all require large quantities of goat and kid skins4 ,it may be pointed out here1 however1 that quite nine-tenths of the so-called kid gloves are made of lamb and sheep skins4 ,in appearance1 there is very little difference between the real kid and the lamb skin gloves1 but the former are more durable and warmer in wear than the latter4 ,with an enormous range of qualities1 it is a difficult task for the goat-skin dresser to find the most suitable sorts for his trade4 ,the skins used in the glove industry are largely obtained from the ,near ,eastern countries1 ,arabia1 ,austria1 ,spain1 and the ,cape4 ,the selections best suited to the making of glazed and patent 7japanned7 kid are found in the ,north-,western provinces of ,india1 ,brazil1 ,china1 ,russia 7especially the ,asiatic provinces71 ,mexico1 the ,cape1 and ,arabia4 ,the ,indian goats known as the ,patnas1 which are collected in the district of ,behar1 are commonly supposed to be the best in the world1 chiefly because of their fine grain and stout substance2 but the best ,brazilian and ,mexican skins are equally good in quality4 ,the best moroccos for fancy articles are made from ,continental skins1 and in this respect ,germany has the great advantage of a good supply of native skins4 ,norway and ,spain also provide skins suitable for real morocco leather4 ,a very large quantity of ,indian-tanned goat skins are imported into ,european countries and dressed for morocco leather4 ,there should be a distinctive name for this class of leather1 as1 although it is similar in appearance1 it is not nearly so good in quality as the real morocco4 ,in addition to cattle hides1 sheep1 and goat skins1 which are the main supply of raw material for leather1 other kinds of hides and skins are utilised4 ,horse hides1 which1 in the ,united ,kingdom1 are graded according to size and quality in four or five selections and sold by the piece1 are largely used on the ,continent1 and especially in ,germany2 nearly all of the ,british production being sold to that country4 ,when chrome tanned1 these hides produce quite a serviceable upper leather of good wearing quality1 but1 owing to their somewhat loose texture1 the characteristic grain of box calf cannot be reproduced naturally1 and the surface of the leather has1 therefore1 to be printed4 ,this style of finished leather does not meet with the favour of ,british boot manufacturers1 and the industry has not been greatly developed in consequence4 ,in view of the increasing cost of other kinds of leather1 however1 more attention may be paid to that made from horse hide1 but the supply of this raw material is very small compared to the production on the ,continent1 where horse flesh is consumed freely4 ,russia produces large quantities of horse hides and colt skins1 most of which are exported to the ,united ,states of ,america1 where they are made chiefly into japanned1 or so-called patent1 leather1 which commands a very high price in relation to the cost of the raw material4 ,next in importance to horse hides is the pig skin1 which produces a wonderfully tough leather4 ,the pig skin leather industry is chiefly confined to ,scotland and ,germany1 the reason being that the skins are left on the carcases in the other parts of the world4 ,on the average1 a pig skin is worth about #fs41 yet it is seldom removed from the carcase4 ,one reason is the great difficulty of flaying the animal2 it appears to be almost impossible by present methods to remove the skin without cutting away a large quantity of fat1 and the value of the skin compared to the loss of weight of the meat offers very little inducement to remove the skin1 in addition to which1 the custom of leaving the rind on bacon and pork effectually prevents any attempt at present to increase the supply of pig skins4 ,this is a great loss to the leather trade1 for the pig skin is particularly suitable for saddles and various kinds of strong leather goods4 ,imitation pig-skin leather is made from hides1 shoulders1 bellies1 or persians1 but real pig skin is distinguished from the imitation by its peculiarly marked grain1 formed of groups of three small holes which penetrate well into the skin and form part of the sheaths of the pig's bristles4 ,among other skins useful for leather are those of the wallaby1 kangaroo1 dog1 lizard1 crocodile1 alligator1 ichneumon1 frog 7,japanese71 deer1 antelope1 and chamois1 while it is said that even rabbit skins have been pressed into service in ,germany1 though they cannot have much value owing to their small size and thin substance4 ,dog-skin leather wears well1 mainly on account of the large amount of natural grease present in the skin1 but the supplies are naturally small4 ,the hides of the walrus1 elephant1 rhinoceros1 hippopotamus1 and other wild animals are also tanned in small quantities1 walrus leather being well adapted for knife and sword polishing4 ,the mammals also contribute their quota to the supply of raw material of the leather trade1 the seal perhaps1 being the most important4 ,this refers to the hairy seal hunted off the ,north ,american coast4 ,the raw skins are shipped chiefly from ,newfoundland1 where the industry of seal fishing is well organised and provides employment for about #f1jjj men4 ,the seal caught in the ,north ,atlantic ,ocean is hairy and quite distinct from the fur seal captured in the ,arctic ,ocean off ,alaska4 ,the skin of the hair seal is only suitable for making into leather1 but there is a layer of fat underneath it which furnishes a valuable raw material for the manufacture of oils and soap4 ,the skins are salted and shipped to ,america and ,england4 ,they are easily distinguished from other kinds of commercial hides and skins by the oily appearance of the flesh side4 ,according to an ,american ,consular ,report1 the results of the fishing during the season #aiac were satisfactory4 ,the total number of seals captured was #bgb1ife1 which were valued at #ih1hjj4 ,the number of skins exported was #bab1bhe1 valued at #fd1cjj1 of which the ,united ,states of ,america bought #aea1cee1 the ,united ,kingdom #fj1ged1 and ,canada #agf4 ,the porpoise1 or sea hog1 has a very useful hide which1 when dressed1 makes a tough leather suitable for laces4 ,the hides of other cetaceous mammals1 such as the whale and narwhal1 are convertible into useful leather4 ,the ,british porpoise laces are generally made from the skin of the white whale 7beluga74 ,,defects ,,of ,,raw ,,hides ,,and ,,skins ,a remarkable feature of the leather trade is the great waste due to the careless preparation of a large number of hides and skins4 ,naturally1 owing to their greatly increased value in recent years1 there has been a decided improvement1 but much loss occurs every day from damage to hides which ought to be avoided4 ,the chief faults are in flaying and curing1 but there are other important defects due to natural causes4 ,bad flaying may be due 7#a7 to cutting holes in the hides or skins2 7#b7 to scoring or siding 7i4e41 cutting into the hide without going completely through71 this generally occurring in the flanks or sides which are the most difficult parts of the hide to remove from the carcase2 and 7#c7 to mis-shaping the hide1 which ought to be left square4 ,any or all of these defects may be found in a single hide4 ,despite the active work of several proprietors of hide markets and the tanners' federations the proportion of badly-flayed hides in ,england constitutes a serious loss1 which1 however1 may not fall directly on either the butcher or the tanner1 for the former may save in wages by employing an inexperienced slaughterman1 while the tanner pays a reduced price for the hide4 ,the losses due to bad flaying and curing in the ,united ,kingdom are mainly attributable to the butchers' preference to kill these beasts in their own back-yard rather than in a public abattoir4 ,many of these small private slaughterhouses ought to be condemned by the authorities2 but very few people outside those immediately interested have taken the trouble to inspect a modern public abattoir where everything is provided to carry on the work expeditiously and hygienically4 ,on the ,continent1 where the conservatism of traders is not permitted to interfere with the public welfare to such an extent as it is in ,england1 public abattoirs have become quite a feature in many cities1 and one of the principal results of the system has been a remarkable improvement in the preparation of raw hides and skins for the tanner4 ,in fact1 a mechanical method of flaying has been invented in ,paris1 and is used extensively at the public abattoirs1 by which hides are removed from cattle without a single mark or scratch4 ,the method is known as dpouille mcanique 7mechanical flaying7 and consists in forcibly removing1 by means of a windlass worked by electric power1 the portions of hide which adhere firmly to the carcase and which are found over the ribs1 the buttocks1 and the tail4 ,the remaining part of the hide can be easily removed with the ordinary butchers' flaying knife or with a heavy hammer of special design4 ,the apparatus required to carry out the mechanical method of flaying1 beyond the fixtures in the abattoirs where the process is adopted1 consist of two lengths of chain to hold the carcase firmly1 two special hammers1 and one pair of strong pincers2 the cost of one set is about #d4 ,mr4 ,gaston ,tainturier1 of ,paris1 is the inventor of this system1 which has added thousands of pounds to the incomes of ,parisian butchers4 ,figure #a is from a photograph taken at the ,islington 7,london7 ,abattoir1 where a demonstration of the process was given by ,mr4 ,tainturier in ,february1 #aiac4 ,naturally1 this method cannot be adopted in small slaughterhouses in back-yards1 but is readily adaptable to public abattoirs1 where practically all of the heavy work is done by electrical power4 ,this exemplifies only one of several advantages of modern abattoirs over private slaughterhouses4 ,although it cannot be expected that the ,english butchers will readily change their prejudice against modern abattoirs1 they are slowly but gradually improving the flaying process in view of the high prices paid for perfect hides4 ,the most progressive of the proprietors of the ,english hide markets are offering money prizes to slaughtermen for the best flayed hides4 ,strictly speaking1 this encouragement should come from the butcher1 who receives the benefit of increased prices for hides removed without a scratch4 ,the ,tainturier system1 however1 gives better results1 no matter how well the hides are removed with the knife4 ,the method is not patented1 and it is open to anyone to adopt it merely for the cost of the apparatus1 yet1 despite this gain1 no butcher outside ,france and ,belgium has yet adopted the method1 although the trade is losing hundreds of pounds every week through bad flaying4 ,several other systems of improved flaying have been devised1 and some of them patented1 but very few have been adopted on a practical scale4 ,one of the most useful consists of fixing a safeguard about a quarter of an inch from the edge of the knife2 this prevents the possibility of cutting holes into the hide1 although it does not1 of course1 prevent scoring1 which is a serious defect in hides made into sole leather4 ,a safe method is to use a sharp knife of hard wood1 such as hickory1 which has been successfully tried in one of the large ,american meat-packing establishments4 ,the hides from these abattoirs are generally well-flayed1 properly cured1 and closely trimmed1 with the result that they command higher prices than any other class of salted hides4 ,the quotations for packer hides are followed with keen interest by tanners in all parts of the world4 ,illustration3 ,,fig4 #a ,,mechanical ,,flaying 7dpouille mcanique7 ,another useful method of preventing damage to the hides by cuts with a knife is that invented by ,mr4 ,e4 ,pim1 a ,liverpool hide factor4 ,the apparatus used is known as the tail extractor4 ,it is of simple construction1 consisting of four pieces of iron riveted together loosely in the shape of a diamond with a clamp attached to secure the tail4 ,the hide is then forcibly removed from the tail and the buttocks by pulling it downward 7,fig4 #b74 ,the importance of this operation can be gauged from the fact that by the use of the butcher's knife both of these parts of the hide are often cut very badly4 ,illustration3 ,,fig4 #b ,,pim',s ,,system ,,of ,,flaying ,even the apparently trivial matter of removing the hide from the cheeks and face is economically important1 for1 unless those parts are removed so as to get the maximum surface1 they are only fit to be cut off and thrown in a pit with other pieces and roundings which are made into glue4 ,imperfect preservation is another serious form of damage to hides and one that cannot be easily remedied in some of the hot climates4 ,hides and skins may be simply dried1 salted and dried1 wet-salted1 treated with arsenic solution and dried1 brined or pickled with acid and salt2 of these methods the last-named is the most effective1 but is not practicable1 or1 at least1 has not yet been applied practically to the cure of hides and calf skins4 ,salt is not available1 or is too costly in most tropical countries2 hence1 ,chinese1 ,indian1 ,mexican1 ,colombian1 and ,arabian hides and skins are generally exported in a dry condition4 ,even when the hides are dried under the best conditions in a cool and shady place1 they are of less value than a fresh or a wet-salted hide1 owing to a certain loss of gelatinous matter in softening them before they can be placed in the lime liquors4 ,but it not infrequently happens that hides are dried by exposure to the hot sun1 or perhaps in a strong current of air4 ,in either case1 the hide is much reduced in value and may be irreparably ruined4 ,the effect of submitting hides to these conditions is that the exterior surface becomes rapidly dry and1 naturally1 contracted1 so that the air or heat cannot reach the interior1 which retains moisture4 ,this moist inner layer may be quite thin1 but it contains sufficient nutrient to develop putrefactive organisms1 so that when the hide is soaked in water it practically falls to pieces4 ,the effect of hot sun or heat of any kind is1 of course1 disastrous to raw hides and skins1 and there have been not a few claims on shipping companies as the result of storing hides near the boilers of ships4 ,salt is almost invariably used for curing both hides and calf skins1 but though it is a good preservative it has one or two minor defects4 ,it contains too much water1 and is liable to contain traces of iron which is inimical to both raw hides and leather in process of manufacture4 ,common salt is also liable to cause stains which cannot be removed in later processes1 and which are even accentuated in the tan liquors4 ,one trade chemist attributes these stains to the presence of calcium sulphate 7,ca4 ,,so#d7 or gypsum in the salt1 which is converted into calcium phosphate by the action of the phosphoric acid in the nuclei of the hide on the sulphate of calcium4 ,another well-known technical chemist is certain that stains are produced by the growth of bacteria1 and to prove his assertion prepared in gelatine several cultures from salt-stained skins4 ,practical men generally attribute the stains to the presence of blood on the hides or skins at the time of curing1 and the majority of the stains are probably due to this cause1 although the presence of calcium sulphate as an impurity of the salt would undoubtedly contribute to this defect4 ,blood contains a percentage of iron1 and1 with other extraneous matters1 should be washed from the hides before salting them4 ,fortunately1 chemists have lately paid attention to the advantages of the use of pure salt in various industries1 with the result that at least two chemically pure products are now available4 ,the use of these salts should be general for the cure of hides and skins1 as they are quite dry1 and1 therefore1 easily spread4 ,as a curing agent1 they are much more effective and lasting than common salt4 ,the use of glauber salts 7,na#b ,,so#d7 is recommended by the ,international ,commission for the ,preservation1 ,cure1 and ,disinfection of ,hides and ,skins instead of ordinary salt1 where the latter is unobtainable4 ,the preparation of a sterilised salt1 however1 renders its export a practical proposition to almost any part of the world4 ,although the loss due to bad curing and flaying is very great1 it is quite small compared with the damage caused by natural defects4 ,the ravages of disease cause a great wastage of hides and skins1 as animals infected with anthrax are immediately destroyed and cremated in all civilised countries1 while1 in ,great ,britain1 foot-and-mouth disease is kept in check by the same drastic method4 ,in many other countries1 the infected cattle are isolated1 treated with an antiseptic hoof-and-mouth wash and generally cured1 as it is a mild fever which soon runs its course1 although it is very contagious4 ,the germ of foot-and-mouth disease has not yet been discovered1 for the most powerful microscope fails to reveal its presence1 but cattle readily show the complaint1 as their hoofs and mouths become covered with swollen lesions4 ,another kind of fever1 known as tick1 was prevalent in the southern part of the ,united ,states1 but this disease was eventually eliminated by systematically dipping the cattle three or four times a year4 ,the cattle dip used effectually prevented the ravages of the fly which caused the disease4 ,a similar method has of late years been adopted in ,south ,africa1 with the result that cattle-raising in that country is developing rapidly4 ,anthrax is due to the presence of bacillus anthracis1 a vegetable organism of ,siberian origin4 ,dry ,chinese and ,russian hides are specially liable to contain the spores of anthrax1 and1 as the disease proves fatal to workmen infected by it unless treatment with anti-anthrax serum be given in the early stages1 hides and skins from infected areas should be disinfected before shipment4 ,the method proposed by ,mr4 ,a4 ,seymour-,jones1 which consists in treating hides with very dilute formic acid and one part of bichloride of mercury in #a1jjj of water1 and afterwards with a saturated solution of salt solution 74#jb per cent47 of bichloride of mercury1 seems to be the most effective without damaging the hides4 ,illustration3 ,,warble ,,fly 7#a7 ,egg1 7#b7 ,larva1 7#c and #d7 ,chrysalides1 7#e7 ,natural form of fly1 7#f7 ,magnified fly4 ,a peculiar natural defect is found in many ,south ,american goat skins1 especially the ,brazilian1 which are often badly scratched by the animals rubbing themselves against cactus plants4 ,although1 perhaps1 more of an artificial than a natural defect1 the scratches caused by cattle rubbing their hides against barbed wire constitute a serious1 but easily avoidable1 loss4 ,such a barbarous system of fencing ought never to be used4 ,illustration3 ,a ,,kip ,,containing #ehd ,,holes ,,caused ,,by ,,the ,,warble ,,fly 7,the skin belongs to ,w4 ,d4 ,mark ,sons1 ,hide ,factors1 ,newcastle47 ,illustration3 ,,fig4 #c ,,hole ,,in ,,cow ,,hide1 ,,made ,,by ,,the ,,grub ,,of ,,the ,,warble ,,fly 7,magnified fifteen times7 ,the most serious loss in connection with hides and skins1 however1 is caused by the warble flies1 hypoderma bovis and hypoderma lineatum1 which lay their eggs on the hides of cattle4 ,it has been a debatable point for some years as to whether these eggs hatched and burrowed their way into the hides from the exterior or were licked and swallowed by the cattle and1 after traversing the digestive tract1 pierced the hide from the interior4 ,professor ,carpenter1 who has been experimenting a number of years for the ,department of ,agriculture for ,ireland1 has succeeded in taking a remarkable photograph 7,fig4 #c7 which proves that the larvae penetrate the hide from the exterior4 ,these develop within the hide and often penetrate to the flesh before they fall out to the ground and change into the fly4 ,the most effective way of getting rid of the pest is to destroy the larvae1 either by cutting them out and crushing them under foot1 or by piercing them with a hot needle4 ,no satisfactory dressing has yet been found1 but ,prof4 ,carpenter states that sulphur dioxide is effectual1 if a good method of applying it can be devised4 ,while sheep skins are immune from the attacks of the warble fly1 they are often damaged by the blow-fly1 lice1 keds1 and ticks2 by scab caused by the action of a mite or acarus2 and by cockle1 which causes a wrinkled grain4 ,the origin of cockle is not definitely known1 but it is a seasonal defect which begins to show on a large number of skins in ,december and does not disappear until the sheep are shorn in the following spring4 ,,chapter ,,iii ,,tanning ,,materials ,tanning materials are derived from the vegetable1 mineral1 and animal kingdoms4 ,the vegetable materials used are woods1 barks1 shrubs1 leaves1 and fruits1 either in their natural state or in the form of extracts4 ,the majority of the minerals have a more or less tanning effect on animal fibres1 but the principal are basic chrome salts1 formaldehyde1 alum and salt4 ,titanium1 iron1 cerium and potassium salts also convert skins into leather1 but are not yet used commercially4 ,the animal matters that will convert skins into leather consist of oxidised oils 7chamois leather71 fats1 and brains 7crown1 ,helvetia1 or ,preller's leather74 ,each of these classes of tanning materials has characteristic effects which render them easily distinguishable4 ,the use of combinations of vegetable and mineral tannins has lately increased1 and it is possible that the blending of the two classes of materials may produce an ideal tannage for certain classes of leather4 ,in fact1 this result is already claimed for a chemically combined tanning material which1 according to the ,american patent1 is prepared by the following method3 #abe lb4 of solid quebracho extract is dissolved in the same weight of hot water and allowed to cool2 #af lb4 of commercial caustic soda dissolved in two or three times its weight of water is added1 and the mixture agitated about half an hour2 #aej lb4 of chromium sulphate is then added4 ,in this way an insoluble tannate of chrome is produced1 but1 on boiling and agitating1 it changes to a greenish brown colour and forms a sulphotannate of chrome4 ,the combination of the alum tannage and gambier 7a vegetable extract7 has been used successfully for years past4 ,another combination which has given good practical results is the tannage with alum and chrome salts in the manufacture of glove leather4 ,the vegetable materials containing tannin should be arranged botanically1 but the following classification is simpler for practical purposes4 ,,natural ,,tanning ,,materials #a4 ,barks4--,oak1 ,hemlock1 ,pine1 ,fir1 ,alder1 ,khaki1 ,willow1 ,cork1 ,mimosa or ,wattle1 ,babool1 ,larch1 ,mangrove1 ,spruce1 ,elm1 ,birch1 ,pomegranate1 ,cebil4 #b4 ,leaves1 ,twigs1 etc4--,sumach1 ,mangrove1 ,mango1 ,eucalyptus1 ,pistacia1 ,lentiscus4 #c4 ,roots4--,canaigre1 ,palmetto4 #d4 ,fruits4--,myrobalans1 ,valonia1 ,divi-,divi1 ,cascalote1 ,mangosteen1 ,pomegranate1 ,celavinia1 ,bablah1 ,algarobilla4 #e4 ,excrescences4--,gall ,nuts1 ,chinese ,galls1 ,pistacia ,galls1 ,tamarisk ,galls4 ,,tanning ,,extracts #a4 ,woods4--,oak1 ,quebracho1 ,hemlock1 ,chestnut1 ,mimosa1 ,mangrove1 ,spruce4 #b4 ,barks4--,oak1 ,wattle or ,mimosa1 ,larch4 #c4 ,shrubs1 ,leaves1 etc4--,gambier1 ,cutch1 ,catechu1 ,kino1 ,sumach4 #d4 ,fruits4--,myrobalans1 ,valonia4 #e4 ,roots4--,palmetto4 ,of these materials1 only about twenty are of much importance commercially1 the principal being oak1 chestnut1 quebracho1 hemlock1 valonia1 gambier1 myrobalans1 mimosa or wattle1 sumach1 mangrove1 divi-divi1 spruce1 larch1 and babool4 ,,oak ,,bark 7quercus robur7 is still an important material1 but is rarely used alone4 ,the bark from ,english oaks contains from #h-ad per cent4 of tannin 7quercitannic acid7 as estimated by the impregnation of a standardised hide powder in a given quantity of the tanning material in solution4 ,owing to its weakness in tannin compared with other materials1 oak bark tans very slowly4 ,used for sole leather1 it would not produce the essential quality of firmness and solidity1 and it is now customary to use a stronger tanning material1 such as valonia1 or valonia extract1 or gambier in the latter stages of the process4 ,this is the nearest approach to the pure oak bark tannage of former days1 and1 if carefully regulated1 is a great improvement on the old method4 ,if dressing hides and calf skins required for boot upper leather are bark-tanned1 the tannage is often completed in a sumach liquor1 the object in this case being to lighten the colour so that the leather can be dyed evenly4 ,in ,england1 oak bark is harvested in ,april and ,may1 when the sap rises in the tree4 ,rings are cut round the tree soon after it is felled and the bark is peeled from the tree with a special tool which is forced between the bark and the wood4 ,it is peeled in narrow strips about #c ft4 in length1 and on delivery to the tannery is stacked in huge ricks4 ,if harvested in a good1 dry condition1 the bark is said to improve with age1 although analytical tests have shown that there is always a certain loss of tannin4 ,an old rick is much darker in colour than a new one1 owing to exposure to the air4 ,coppice bark from young trees is preferred by tanners1 as it is free from ross and generally contains more tannin than the rough bark4 ,in view of the modern demand for materials in extract form1 ,english oak bark would almost certainly be preferred in the form of a concentrated liquid1 if the supply of the raw material was plentiful within a limited area4 ,during the last few years it has not met with a ready sale1 owing to the large supply of other materials1 but it would doubtless regain some of its former popularity if it were prepared in the form of an extract containing about #be per cent4 of tannin4 ,the only oak bark extract on the market is the ,american chestnut oak 7quercus prinus74 ,,oak ,,wood is very largely used for the manufacture of tanning extract1 especially in ,hungary and ,canada4 ,the extract contains from #bd-bh per cent4 of tannin1 and is extensively used in the tannage of heavy leathers1 as it strengthens the liquors and hastens the process1 while keeping the quality of the leather at a high standard4 ,,valonia 7quercus aegilops7 is the acorn cups of an oak tree which grows abundantly in ,asia ,minor and the ,greek ,archipelago4 ,no other part but the acorn cups is exported4 ,the harvest in ,asia ,minor takes place in ,august1 when the fruit ripens and the cups can be easily beaten from the trees4 ,they are left to dry on the ground and are then sent to stores in seaport towns1 and principally to ,smyrna4 ,the drying is still further completed in spacious warehouses1 where the cups are spread out and turned over until fermentation ceases4 ,during this process the acorns shrink and are rejected4 ,the cups should be perfectly dried and very hard before export4 ,the ,turkish valonia contains from #cj to #ce per cent4 of tannin1 and is of much better quality than the ,greek1 which is usually harvested before it is ripe1 and1 therefore1 contains the acorn4 ,as the acorn has practically no tannin value1 the ,greek valonia contains only #be to #bh per cent4 tannin4 ,there are several grades of valonia1 the best going to ,russia1 ,austria1 and ,italy4 ,english tanners seem to prefer the lower qualities at present1 probably because the price is much less than that of the best grade4 ,the beard of the valonia cup is much richer in tannin than the shell1 and1 as several of the spines become detached during the storage of the material1 there is always a certain quantity of beard 7trillo7 on offer4 ,this may contain up to #db per cent4 of tannin1 but its price is usually the same as that of ordinary valonia4 ,of late years1 very large quantities of valonia have been made into extract at two works in ,smyrna4 ,the production of extract will no doubt increase1 with a corresponding reduction in the export of the raw material4 ,the great advantages of the extract over the natural cup are its superior strength of tannin 7#fj to #fe per cent471 easier solubility1 uniformity of quality1 lower cost per unit of tan1 and guaranteed purity4 ,valonia is well adapted for the tannage of sole leather in conjunction with oak bark1 for it deposits a heavy bloom 7ellagic acid71 imparts weight and solidity1 and increases the resistance of the leather to moisture4 ,,the ,,chestnut ,,tree 7castanea vesca7 probably provides the next tanning material of importance4 ,this must not be confused with the chestnut oak1 an ,american tree which also yields a very useful tannin4 ,the chestnut is indigenous to the ,south of ,france and ,italy1 where the forests have been considerably reduced in size to meet the great demand for this popular tanning material4 ,the greater part of the denuded forests have not been replanted with the chestnut1 as the land has been put under cultivation whenever possible4 ,a further depletion has been caused by the ravages of an insect1 which turns the interior of the wood quite black and renders it unfit for tanning purposes4 ,it will1 naturally1 be several years before the supply is exhausted1 even if no reafforestation is undertaken4 ,as it is the most important tanning material grown in ,france1 and the chestnuts are used as a food1 steps may be taken to cultivate the trees on areas unsuitable for agriculture4 ,liquid chestnut extract contains from #cj to #cb per cent4 of tannin1 and1 when decolorised1 gives a light brown colour to the leather4 ,it is rarely1 if ever1 used alone1 but generally in conjunction with quebracho1 valonia or myrobalan extracts4 ,,the ,,chestnut ,,oak ,,tree is indigenous to ,america and the wood yields a very good tanning extract1 containing up to #cj per cent4 of tannin4 ,this material is the principal tanning agent used in ,america1 where the tannages are roughly classified in three sections3 7#a7 oak1 7#b7 hemlock1 and 7#c7 the union 7i4e41 a mixture of hemlock and oak74 ,american tanners also use other materials to a smaller extent1 chiefly for blending with the principal tannins4 ,quebracho and spruce extracts are specially favoured4 ,,quebracho ,,colorado is a tree indigenous to ,south ,america1 the best wood for tanning purposes being found in the ,gran ,chaco district in the north of ,argentina1 and in ,uruguay4 ,the wood contains from #ag to #bb per cent4 of tannin1 and is so hard and heavy that it sinks in water4 ,in fact1 its name is derived from two ,portuguese words meaning axe-breaker4 ,after felling the trees1 they are cut up into logs about #d ft4 in length and either exported in this state to ,hamburg1 ,havre1 and ,liverpool1 or sent to the numerous factories in close proximity to the forests to be made into extract1 in which an enormous trade has of late years been developed4 ,very little of the natural material is now used1 as1 even after cutting the wood into chips1 the tannin is extracted only with great difficulty1 whereas the extract can be treated with sulphites1 alkalies1 or neradol 7the artificial tannin7 to render it easily soluble1 besides which the concentration of the material raises the percentage of its tannin to #fe or even #gj per cent4 ,owing1 perhaps1 to faulty preparation1 this tanning extract was not well received at first1 but it is now among the principal tannins and increases in importance every year4 ,,myrobalans is the unripe fruit of an ,indian tree 7terminalia chebula7 and contains from #ce to #dj per cent4 of tannin which gives a light colour to leather4 ,this material is useful both for light and heavy leathers1 but is generally used in admixture with other tannins4 ,it deposits much bloom 7ellagic acid7 and is largely used for brightening the dark colour produced by other tannins4 ,a large quantity of this material is now made into extracts1 which are more convenient to handle and more uniform in strength of tannin4 ,natural myrobalans have the appearance of shrivelled nutmegs1 except that they are yellowish in colour2 they are very hard and require a special milling machine to reduce them to powder4 ,the quality of myrobalan nuts varies in different districts1 the best being ,bhimlies and ,jubbalpores4 ,,sumach is a valuable tanning material1 and is used for a large proportion of the light and fancy leathers4 ,it is a small bush plant which grows in ,italy1 ,spain1 ,southern ,france1 ,america1 and ,algeria1 but of the numerous varieties the ,sicilian 7rhus coriaria7 is by far the most important4 ,sumach is one of the few materials cultivated on an extensive scale2 most tanning materials are derived from natural sources and1 chiefly owing to the length of time before trees reach maturity1 it would not be a paying proposition to cultivate them4 ,the sumach shrubs are propagated from small cuttings and the leaves can be picked at the end of the first year1 but it is better to allow the shrubs to become more firmly established before stripping them4 ,the leaves are dried and sometimes exported whole1 especially for the use of the silk manufacturers in ,lyons2 but they are more often ground to a fine powder4 ,all sumachs should be ventilated to remove foreign matters and all traces of iron1 which would cause dark bluish stains on the leather4 ,ventilation is effected by passing currents of air1 preferably with a fan1 through a narrow room1 when the pure sumach is sent forward1 while the heavier particles of dirt and small pieces of wood remain behind4 ,sometimes the process is repeated1 and the best brands of sumach are generally described as pure1 extra ventilated4 ,as far as possible1 the male plants 7mascolino sommacco7 are cultivated in ,sicily1 where the best sumach is grown4 ,female sumach 7femminello sommacco71 grown in parts of ,italy1 is weaker in tannin than the male1 but is rarely sold separately4 ,the serious amount of adulteration formerly practised by the admixture of inferior plants1 and particularly of lentisco 7pistacia lentisco7 led to the ,italian ,government taking strong action a few years ago1 and it is now possible1 for a very small sum1 to have any consignment inspected and analysed by the ,government4 ,lentisco is now sold separately and is used for common work4 ,sumach has been successfully introduced into ,australia1 but its development is retarded owing to difficulties of labour1 which render competition with the ,european product almost impossible4 ,an inferior sumach 7rhus glabra7 is grown in ,america1 chiefly in the ,state of ,virginia4 ,it contains from #ae to #bj per cent4 of tannin1 and produces a darker coloured leather than ,sicilian1 the best qualities of which contain #bg to #cj per cent4 of tannin4 ,a useful test for finding out if a sumach has been adulterated is to treat a small quantity with strong nitric acid1 which destroys the structure of the leaves4 ,the mass is washed and neutralised with an alkali1 when the appearance of the midrib and veins of the leaves of the common adulterants are easily recognised4 ,sumach is not so much used for shoe upper leather as it formerly was1 but it is the best tanning agent for many kinds of fancy light leathers1 such as bookbinding1 calf1 and skivers 7the grain of split sheep skins71 moroccos1 furniture leather1 etc4 ,it is also less subject to the action of the air and gaslight than any other tanning material1 and is strongly recommended for tanning purposes by a special committee appointed by the ,society of ,arts to enquire into causes of the rapid decay of leather bindings4 ,sumach is very useful for brightening up the colour of leather tanned with darker tannins1 and is frequently used for improving the colour of both dressing and sole leather4 ,by itself1 it yields an almost white leather which affords a good foundation for the most delicate shades4 ,,gambier or ,,terra ,,japonica 7uncaria gambir7 is a crude extract of a shrub indigenous to the ,malay ,peninsula4 ,nearly the whole of the production is shipped from ,singapore4 ,the leaves and twigs are boiled in an iron vessel1 and when the mass has become syrupy it is strained through a rough sieve into a shallow tub1 where it is cooled4 ,the liquor is stirred while cooling and rapidly thickens4 ,before it sets1 it is cut into #a in4 cubes and thoroughly dried4 ,good qualities contain from #ej-fe per cent4 of tannin4 ,an inferior product1 called block gambier1 is made by allowing the syrupy mass to set in large blocks weighing about #b cwt4 each4 ,these are packed in coarse matting4 ,the strength of tannin varies from #cj to #dj per cent4 ,gambier is a good tanning material1 but its use has been declining for some years past owing to its being frequently adulterated with sago and other farinaceous plants4 ,however1 a pure gambier extract1 manufactured on the latest scientific principles1 has been placed on the market1 and there will undoubtedly be a revival of the use of this valuable tannin4 ,this pure gambier is prepared at ,asahan1 in ,sumatra1 and is guaranteed to contain a minimum of #ch per cent4 of tannin4 ,gambier can be used to advantage in keeping up the strength of bark liquors in the tannage of sole leather and hastening the process1 while it may be used alone for the tannage of boot upper leather and dressing hides4 ,it produces an exceptionally mellow and plump leather4 ,it is preferable1 however1 to complete a gambier tannage with a little oak wood or quebracho extract1 in order to fix the tannin principle of gambier1 which1 perhaps on account of its viscosity1 does not readily combine with the fibres of the skin4 ,,mangrove or ,,mangle1 a tree found on the coasts of several tropical countries1 yields a useful bark for tanning purposes4 ,at low tide1 these trees show their great arched roots standing high above the ground4 ,the best varieties1 the ceriops species1 are found in the ,east ,indies and ,bengal1 and the bark of these is said to contain sometimes nearly #dj per cent4 of tannin4 ,other varieties contain from #ae to #be per cent4 ,the bark is generally made into a solid extract1 or cutch1 in which form it contains more than #fj per cent4 of tannin1 ,it is useful to blend with other materials1 such as oak wood1 chestnut1 and quebracho extracts1 but used by itself it imparts a strong reddish colour to the leather4 ,some of the ,indian varieties are used as dyeing materials1 and act as a satisfactory mordant in dyeing leather a dark shade4 ,,mimosa or ,,wattle trees1 which belong to the acacia species1 yield bark rich in tannin4 ,australia is the native country of several varieties1 including the ,black ,wattle 7acacia pycnantha71 the ,golden ,wattle 7,a4 longifolia71 and the ,green ,wattle 7,a4 decurrens74 ,the bark contains from #bj to #de per cent4 of tannin4 ,the cultivation of wattle in ,australia seems to have declined1 owing to the high cost of labour and inability to compete with the mimosa bark imported from ,south ,africa1 where it is cultivated on a very large scale and where labour conditions are more favourable for the growers1 as is clearly shown by the fact that the wattle growers in ,australia successfully petitioned the ,government a short time ago to place a duty of #a #ajs4 per ton on the imported bark4 ,the introduction of the industry into ,south ,africa was quite an interesting adventure4 ,a ,mr4 ,vanderplank brought the seeds from ,australia to ,england about seventy years ago1 and afterwards took them to ,south ,africa1 where1 in recognition of certain services a few months after his arrival1 he was granted a farm by the ,dutch ,government4 ,he then planted the seeds of the black wattle1 which grew so well that it was only a question of developing the industry4 ,it was some years before any ,african bark was exported1 and only #aa worth was shipped in #ahhf4 ,in #aiaa1 the exports had risen to #bhh1jjj4 ,wattle trees can be grown on soil that is unsuitable for agriculture1 and there is every prospect of the industry expanding in ,south ,africa1 where a factory has lately been established for the purpose of converting the bark into an extract1 which1 it is said1 will contain between #ej and #fj per cent4 of tannin4 ,by far the greater proportion of wattle bark is still exported in the natural form1 ground or chopped1 and packed into bags weighing about #a cwt4 each4 ,before the ,european ,war nearly the whole of the bark was shipped to ,hamburg1 ,english tanners taking very little interest in it1 although it was largely used by ,german tanners4 ,but since the supplies of the materials favoured by ,british tanners have become somewhat restricted1 attention has been drawn to the value of mimosa bark4 ,,divi-,,divi 7caesalpinia coriaria7 is the dried pods of a ,central ,american tree4 ,it has also been successfully cultivated in ,india4 ,the pods are rich in tannin1 containing anything from #dj-ej per cent41 but its value is discounted by its liability to fermentation1 which1 however1 may be checked to some extent by the use of antiseptics1 such as carbolic acid1 formaldehyde1 or by the addition of synthetic tannin1 neradol4 ,if this tendency to fermentation and oxidation of the colouring matter could be checked completely1 divi-divi would be a valuable material1 as it makes a firm leather of good colour4 ,when dried1 the pods curl up in the shape of the letters ,s and ,c4 ,the tannin is found in the husks of the pod4 ,the seeds1 which contain no tannin1 are so hard that it has not yet been found profitable to extract the oil from them4 ,very similar tanning materials to divi-divi are cascalote1 indigenous to ,mexico1 and algarobilla 7caesalpinia brevifolia7 which grows in ,chili4 ,cascalote is chiefly used by ,mexican tanners and is rarely exported4 ,algarobilla is not available in large quantities1 otherwise it would be largely used in ,great ,britain1 as it does not ferment so readily as divi-divi1 and is even richer in tannin4 ,,celavinia 7also spelt celavina and cevalina7 has been on the ,english market since #aije1 but has only lately been sold in large quantities4 ,the scarcity of some of the popular tanning materials since the outbreak of the ,european ,war resulted in enquiries for materials that were very little known1 and celavinia has proved worthy of attention4 ,it consists of the seed pods of the tree caesalpinia tinctoria1 which grows abundantly in certain districts of ,central and ,south ,america4 ,the pod is from #d to #f in4 long and is flaky when dried4 ,it contains #cj to #cb per cent1 of tannin of the pyrogallol class1 and gives a very light-coloured and almost white leather4 ,it is the only pyrogallol tannin which does not deposit bloom1 or ellagic acid1 on the leather4 ,it may be used as a substitute for sumach in tanning1 but has not the same bleaching effect in the retanning process4 ,a tanning extract of celavinia would be useful for some classes of light leathers1 where paleness of tint is important4 ,it is difficult to make a second extraction of tannin in the case of the natural material1 as1 after the first extraction1 it forms a soft pulp1 through which water will not easily percolate4 ,,hemlock 7abies canadiensis7 is an important tanning material1 both the bark and the wood being extensively used in ,america4 ,the wood is now generally converted into extracts in factories built near the principal forests4 ,of late years1 this extract has been imported into the ,united ,kingdom in fairly large quantities1 in order to produce a cheap red sole leather to compete with the ,american hemlock-tanned leather4 ,it contains only about #be per cent4 of tannin1 but its value is increased by its contents of insoluble non-tannins1 which give weight and solidity to the leather4 ,hemlock really gives a strong1 durable leather1 but in ,america the practice of using artificial weighing materials1 such as glucose and ,epsom salts1 with a reduced quantity of tanning material1 has considerably lowered the value of this leather4 ,in addition to the materials described1 there are several of minor importance which can only be briefly mentioned4 ,,larch ,,bark is obtained from the tree larix ,europea1 which is found in ,scotland and ,north ,europe4 ,it contains #aj-ab per cent4 of tannin1 which gives a light colour and pleasant odour to leather4 ,scotch basils 7sheep skins7 are tanned with this bark4 ,,birch ,,bark1 from the white birch1 betula alba1 is another aromatic tanning material4 ,it contains only about #e per cent4 of tannin1 and is1 therefore1 generally used with other tanning materials4 ,it contains a tar which imparts an agreeable scent to the leather that protects it from the ravages of insects4 ,in conjunction with willow bark 7salix arenaria7 it is used in the tanning process for the real ,russia leather4 ,an oil containing the scent can be extracted from the birch bark by dry distillation1 and this extract is sometimes used during the dyeing process1 in the manufacture of imitation ,russia leather1 which1 however1 only retains the scent for a few months1 whereas the real ,russia leather has a permanent odour4 ,,canaigre 7rumex hymenosepalum7 is the tuberous root of a dock plant indigenous to ,mexico and the ,southern ,states of ,america4 ,it is fairly rich in tannin 7#be-cj per cent47 and yields a moderately firm leather4 ,it contains too large a proportion of starch1 however1 and cannot be described as a really satisfactory tannin4 ,moreover1 it is not harvested economically and the only way to make a satisfactory tannin of it is to convert it into extract and remove the starchy matters near the source of supply1 if anyone dare take the risk of establishing a factory in ,mexico4 ,,bablah or ,,babool 7acacia arabica or acacia vera7 grows in ,india1 ,egypt1 and the ,sudan4 ,the bark of the babool tree is one of the principal tanning materials used in ,india for hides1 calf1 and sheep skins1 which are sent in large quantities to ,great ,britain in a rough-tanned state and dressed there4 ,it contains #ae-bj per cent4 of tannin1 which readily oxidises in the leather in contact with light1 turning into a bright pink colour4 ,it also seems to weaken the fibres of animal tissues1 and1 for that reason1 babool-tanned leather was condemned by the ,society of ,arts ,commission on ,bookbinding4 ,the pods contain from #bj-cj per cent4 of tannin and give a mellow and plump leather similar to that produced by gambier4 ,the bleaching of the material is troublesome1 and it is probable that its use would be increased if the tannin were prepared in the form of extract4 ,,cutch is a crude extract made from the ,indian tree acacia catechu4 ,this is the real cutch1 as distinguished from the mangrove cutch4 ,it is very rich in tannin 7#ej-fj per cent471 but contains a large proportion of insoluble matter and is1 therefore1 very little used for tanning4 ,it is well adapted for the dyeing of dark colours or black with mineral strikers1 such as chrome and iron salts2 but its chief use is for tanning fishermen's nets1 which it renders waterproof4 ,commercial tannic acid1 used for medicinal purposes1 is prepared from galls or excrescences on oak trees growing in ,asia ,minor4 ,these galls are caused by an insect 7cynips7 puncturing the small branches and producing abnormal growth in the perforated parts4 ,the acid is gallotannic1 which1 if used for making leather1 would produce a soft1 spongy1 and nearly white leather4 ,this tanning material is used a little by ,near ,eastern tanners1 but the result is unsatisfactory4 ,,classification ,,of ,,tanning ,,materials ,tanning materials are divided into two main classes3 7#a7 ,pyrogallol1 7#b7 ,catechol4 ,the pyrogallol tannins give a bluish-black colour1 and the catechol tannins a greenish-black1 with iron salts4 ,bromine water does not precipitate pyrogallols1 but causes a precipitate with catechols4 ,pyrogallols yield ellagic acid 7called bloom in the trade71 which improves the waterproof qualities of leather4 ,on the other hand1 catechols contain a large proportion of insoluble reds1 or phlobaphenes1 which are deposited between the fibres and thus give solidity to the leather4 ,pyrogallol tannins give a light coloured1 soft leather1 and can be used alone satisfactorily2 but heavy leathers1 such as sole and belting1 need a blend of both kinds of tannin4 ,the pyrogallol tannins include sumach1 chestnut1 myrobalans1 divi-divi1 oakwood1 algarobilla1 chestnut oak1 willow1 and galls4 ,the catechols include quebracho1 gambier1 hemlock1 mimosa or wattle1 mangrove1 larch1 birch1 canaigre1 and cutch4 ,oak bark and valonia contain some of the properties of both classes of tannins4 ,there are sub-divisions of these two classes1 arranged according to chemical tests1 by which one tanning material can be distinguished from another4 ,,tanning ,,extracts ,the manufacture of extracts from vegetable tanning materials has increased so rapidly of late years that the process of tanning has undergone radical changes2 and1 whereas the tanner was limited to three or four materials thirty years ago1 he now has the choice of about twenty good materials4 ,these tannins can be suitably blended to produce first-class leather4 ,the processes in extract manufacture are few4 ,the wood1 bark1 or fruit is broken up into small pieces and macerated in hot or cold water4 ,the concentration of the liquid is done in vacuum1 or in an evaporator4 ,the latest method is to treat the tan liquor in a triple-effect evaporator 7,fig4 #d71 the object of using three compartments being to economise in steam4 ,this apparatus makes liquid extracts2 where a powdered or crystal extract is required1 the liquid is afterwards treated in a vacuum drying apparatus4 ,some extracts contain a lot of colouring matter and insoluble substances4 ,to overcome this defect1 they are clarified with blood albumen1 sulphites1 casein1 or acetate of lead4 ,illustration3 ,,fig4 #d4--,,triple-,,effect ,,evaporator 7,blair1 ,campbell ,mc,lean1 ,ltd47 ,,synthetic ,,tannins ,the discovery of a synthetic tannin1 in #aiaa1 by ,dr4 ,stiasny1 who was then an assistant in the ,leather ,industries ,department of ,leeds ,university1 created a great deal of interest in the leather trade1 and can certainly be regarded as a triumph of the application of chemistry to industry4 ,it was thought at first that these tannins might play as important a part in the leather trade as the synthetic dye-stuffs have1 but it is now generally believed that this will not be the case4 ,their use is likely to be as an aid to tanning1 rather than as a complete tanning agent1 although it has been found practicable to use them for one or two classes of light skins1 where it is essential that the colour of the leather should be nearly white4 ,the original patent was taken out in ,september1 #aiaa1 in ,austria1 the native country of the inventor1 but the patent rights have also been protected in other countries1 while the manufacture and sale of the product passed into the hands of a large ,german dye firm1 who have since taken out several patents for other synthetic tannins4 ,the original tannin is produced by treating a sulphonated phenol with formaldehyde4 ,a patent had been taken out several years before for the use of formaldehyde in tanning1 but this expired early in #aiaa2 many patents had also been granted for sulphonated phenol preparations1 chiefly as disinfectants1 but it was left to ,dr4 ,stiasny to discover the value of combining the two chemicals by the process of condensation4 ,the preparation1 first known as neradol1 is now made in ,england under licence1 but1 since the war1 its cost has been more than doubled1 so that it is unlikely to replace natural tanning materials to any great extent4 ,formaldehyde itself has certain properties which are harmful to leather1 and it must be used with extreme caution and in small quantities to avoid these defects4 ,it is used in the leather trade chiefly for keeping up the substance of hides during the tanning process1 and thus causing a rapid absorption of tannin4 ,at the beginning of the tanning process1 the liquors are acidified1 preferably with a weak organic acid1 which causes the fibres of the hides to distend4 ,it is at this stage that the formaldehyde is used4 ,this method1 which cannot improve1 but may easily damage1 the leather1 is almost entirely confined to the ,continent4 ,formaldehyde has a hardening and tanning effect on animal tissues1 and leather treated by this process often has inferior wearing qualities4 ,in the case of the artificial tannin1 this property of formaldehyde is to a large extent modified by the chemical reaction with a sulphonated phenol1 the addition of which also increases its tanning effect2 but1 while the tannage is very rapid1 especially in the case of light skins1 leather produced solely by means of artificial tannin has a slight tendency to dryness after being in stock for some time4 ,no doubt1 however1 methods will be found to overcome initial difficulties1 and various liquors will be prepared to meet different requirements4 ,the question of price remains the deciding factor as to its use on an extensive scale1 for1 while it is so high1 natural tanning materials will be preferred1 except in a few special cases4 ,according to the hide-powder method of tannin analysis1 ,neradol contains about #cj per cent4 of tannin1 but there are many natural tannin extracts containing nearly double the amount of tannin at nearly half the price of the artificial tannin2 the latter1 however1 has a more rapid action and also produces a nearly white leather4 ,another advantage of ,neradol is that it prevents drawn grain1 so that1 if raw hides be treated with a small quantity before tanning1 stronger vegetable tan liquors may be safely used to hasten the process4 ,in the manufacture of sole leather1 for example1 limed hides1 after washing in water1 may be suspended in a solution of ,neradol containing #c to #e lb4 per #ajj gal4 of water for twelve to twenty-four hours4 ,this quantity produces a slight tanning effect1 the hides are thoroughly delimed1 and strong vegetable tan liquors may then be used to complete the tannage without the grain of the hide being drawn or dark in colour1 as would be the case if the hides were not first treated with the artificial tannin4 ,neradol is also said to be an effective bleaching agent for tanned leather in a #e per cent4 solution for a few hours1 without any loss of weight4 ,this property may also be utilised in the production of chrome leather1 where a whiter colour is required than that produced by the ordinary chrome tannage4 ,for this purpose it may be used in a pickling liquor before the one-bath process1 or in the second bath of the two-bath tannage4 ,for dressing wool and fur skins1 the synthetic tannins are much superior to the alum and salt process4 ,,chapter ,,iv ,,leather ,,working ,,machinery ,when it is considered that the construction of machinery for the leather trade had barely started thirty years ago1 the wonderful variety and utility of modern machines are remarkable1 and it is a moot point whether engineering science has not played as great a part as1 or even greater than1 applied chemistry4 ,excepting the bark mill1 various kinds of tumblers1 the fulling stocks1 glazing and rolling machines1 there were practically no efficient mechanical aids to lighten the exceedingly laborious operations incidental to leather manufacture two decades ago2 but so many improvements have lately been made in the construction of machinery for practically every operation in the trade that most of the machines require very little skill to work them1 and can be operated by intelligent youths after a few weeks' experience4 ,the change has been of great benefit to the health of the workers1 for the continual stooping over beams and sloping tables1 combined with the arduous nature of the work1 was very injurious4 ,the reputation that tanning had as a healthy occupation was due more to the work of the labourers than that of the skin workers4 7,the old-fashioned lime-yards and tan-yards were generally in the open1 whereas modern tanneries are roofed47 ,leather trades machinery was not a success at first1 probably because it was very difficult to get the necessary information from leather manufacturers4 ,however1 as the engineers gained more experience of the methods of leather-making1 the defects were gradually remedied until it may be truly said that the machines now reach a high state of perfection4 ,it was no uncommon thing for workmen to lose a finger or two in a machine1 but such accidents are now rare1 owing to improvements in the construction of the machines4 ,most of the machines used in the leather trade are of the cylinder type1 the raw skins or leather passing between two rollers1 of which the upper one performs the operation while the lower one helps to draw the material through the machine4 ,to prevent accidents and control the working of machines1 a third roller is often used1 which serves to feed the leather or skins to the working cylinders4 ,of this type of safety roller1 the ,seymour-,jones attachment to the shaving and buffing machine is of great importance4 ,illustration3 ,,fig4 #e ,,shaving ,,cylinder ,the operations of the tannery1 which are performed by cylindrical machines1 are dehairing1 fleshing1 scudding1 samming1 shaving1 scouring1 striking-out1 setting1 boarding1 buffing1 graining1 printing1 embossing1 and blacking or colouring4 ,the working cylinders usually vary according to the character of the operation1 although one or two types may be used for at least three different operations4 ,where cutting or paring is done1 the working cylinder is fitted with brass blades1 or steel blades backed with iron4 ,the blades are spiral in some machines1 and are so arranged that half of them converge to the left1 and half to the right 7,fig4 #e74 ,when in work1 this type of cylinder not only performs the operation for which it is specially intended1 but also stretches the leather outward1 by reason of the arrangement of the blades or knives4 ,the blades overlap one another to obviate marking1 for if the blades met exactly at the centre they would make a line on the leather4 ,figure #f shows another arrangement of knives for the process of buffing4 ,illustration3 ,,fig4 #f ,,bladed ,,cylinder ,,for ,,buffing ,,leather ,illustration3 ,,fig4 #g ,,band-,,knife ,,splitting ,,machine ,the most important machines outside the working cylinder type are the splitter1 and the glazer4 ,there are several kinds of splitting machines1 but the band-knife machine 7,fig4 #g7 is the most largely used4 ,this is a veritable triumph of the engineer's art1 for it is possible to make five or six layers1 all about the same size1 out of one hide1 although leather is only split once or twice as a rule4 ,of course1 sole1 belting1 and other thick leathers are not usually split4 ,the invention of the belt-knife splitting machine revolutionised the leather trade1 and there would undoubtedly have been a great shortage of leather without it4 ,formerly1 all the levelling and reducing of substance was done by paring off quite small pieces with the shaving knife 7,fig4 #h71 a difficult and laborious work4 ,these parings were only suitable for pulping and compressing into leather board2 but now the flesh splits removed by the machine can be curried1 enamelled1 printed1 or rolled to make serviceable leathers1 although1 of course1 not nearly so good in quality as the top or grain split4 ,the main working part of the splitting machine is an endless steel knife which passes round two wheels placed at opposite ends of the machine4 ,the leather is drawn to the knife through two rollers1 of which the lower one is in sections to allow very thick parts of the hide to pass through the machine4 ,it would need a large volume to describe in detail all the different machines used in the leather trade2 the constructional details of only one machine can be given1 and1 in view of its importance1 the shaver is selected4 ,reproductions of other machines will appear in succeeding chapters4 ,illustration3 ,,fig4 #h ,,shaving ,,knife ,nearly every leather trades' engineer constructs shaving machines1 but the ,howard-,smith is described here1 not because it is the most popular 7unfortunately there is a decided preference for low-priced machines71 but because it is one of the best from an engineering point of view1 and because several improvements are embodied in its construction4 ,illustration3 ,,fig4 #i ,,shaving ,,leather 7,old method7 ,this machine consists of nearly one hundred parts and each is made of the best material available4 ,the advantage of this is obvious when the question of repairs is fully considered4 ,the first ,howard-,smith machine made has been running more than four years1 and has not cost the owner a penny for repairs1 beyond1 of course1 the expense of replacing the blades of the working cylinders2 whereas it is no uncommon occurrence for a cheap machine to be thrown on the scrap heap after a few years' wear4 ,it is always advisable1 therefore1 to buy machinery of the best grade4 ,illustration3 ,,fig4 #aj ,,drawing ,,of ,,shaving ,,machine ,figure #aj represents a drawing of the shaving machine1 ,a being the side view1 and ,b the front4 ,the work of the draughtsman generally appears to the uninitiated to border on the miraculous2 he is often the designer and architect of the machine1 and his work is certainly interesting and skilful4 ,many of the heavy parts1 such as main castings1 pedestals1 etc41 are made in the foundry1 which may be part of the leather trades' engineer's works if he is in a large way of business4 ,the finer parts1 those which might be termed the fittings1 are made in the turnery department2 while the machine is assembled in the fitters' shop4 ,figure #aj ,a shows the side1 and #aj ,b the front construction of the shaving machine4 ,the figures indicate1 by following the arrows1 the principal parts of the machine1 which are shown in detail in sectional tracings4 ,for example1 ,t4 #fe1 of which no working parts are shown in the diagram of the complete machine1 is reproduced in detail in a separate drawing shown in ,figure #aa4 ,each part of the machine is numbered and entered in a stock-book4 ,in describing the principal parts indicated in ,figure #aj1 it will give an idea of the assembling of the machine if a beginning be made with the main iron castings4 ,these comprise the main bed 7#fd71 two side frames 7#fb71 and the front frame 7#eh74 ,the side frames are strengthened by the ribs which form the edge1 and which are about three times as thick as the body of the casting4 ,the object of the front frame is to support the foot lever 7#ei71 the rocking frame 7#eg7 carrying the rubber roll 7#gi71 and the wooden roof 7#ge7 over which the leather is passed4 ,the spring 7#gf7 pulls back the rocking frame 7#eg7 when relieved by the operator removing his foot from the lever 7#ei74 ,the long spring 7#gg7 lifts up the foot lever 7#ei7 when the latter is released4 ,the pullies 7#gc7 are connected with the knife cylinder which shaves the leather4 ,the cylinder is obscured by the wheel-guard 7#fe7 and is1 therefore1 shown separately4 ,this cylinder is comprised of a shaped piece of steel 7turned out of solid metal bars of #d-c_/d in4 diameter7 into which spiral steel blades are caulked with copper or brass4 ,when turned1 the body of the cylinder is #d-e_/h in4 in diameter1 but the parts forming the bearings are reduced to #a-a_/b in4 ,the number of blades is twelve1 fourteen1 or sixteen1 according to the kind of leather shaved1 and to the choice of the operator4 ,it is interesting to note that these blades are now being made in ,sheffield1 although1 before the war1 they had to be imported4 ,the knife guard 7#fe71 shown in detail in ,figure #aa1 is an ingenious contrivance which prevents the operator's hands being drawn into the machine4 ,it consists of an automatic shutter worked by a steel chain from the foot lever4 ,figure #aa a represents the shutter closed down on the knife with the rubber roll1 on which the leather is carried to the knife1 at a safe distance from the shutters4 ,fig4 #aa b shows the position when the machine is shaving the leather1 the guard being clear and the rubber roll engaged with the knife4 ,illustration3 ,,fig4 #aa a4 ,illustration3 ,,fig4 #aa b4 ,in order to sharpen the blades of the cylinder1 a carborundum wheel is fixed in close proximity1 its position being indicated in the drawing by the wheel cover 7#fg74 ,a bracket for feeding the wheel to the blades when grinding them is shown at #ff4 ,when grinding the blades1 the saddle 7#fh7 carries the wheel backwards and forwards across them4 ,a special feature of the saddle in this particular machine is the double-thread screw1 one a right hand1 and the other a left hand4 ,the saddle 7#fh7 is actuated by a swimmer1 as the makers term it1 which engages1 say1 first the right-hand thread2 when the saddle has travelled to the end of its movement the swimmer automatically enters the left-hand thread1 and the saddle is rotated in the opposite direction4 ,the swimmer can be disengaged instantaneously4 ,a brush 7#ee7 is fixed near the cylinder to remove any leather shavings adhering to the blades4 ,it also acts to some extent as a fan1 and1 by creating a current of air1 carries the leather dust away from the operator4 ,a trough is filled with water to catch the dust from the carborundum wheel1 while the knives are being ground4 ,the trough should be cleared out and refilled with clean water from time to time4 ,it is essential that no dust from the grinding wheel comes into contact with vegetable tanned leather required in a natural or colour finish1 otherwise it will cause iron stains1 which are difficult to remove without damaging the leather4 ,for this reason1 the knives should not be ground while this class of leather is being shaved4 ,an important detail of the machine under description is a trueing device4 ,knives are often roughened owing to the carborundum wheel wearing irregularly4 ,the trueing device keeps the wheel perfectly true by means of a diamond held in the end of a screw 7#gh74 ,another ingenious arrangement 7patented7 is a spring 7#gi;a7 placed at the back of the rubber roll 7#gi71 which enables the roll to spring back when the leather1 or any part of it1 is too thick for the cutting cylinder4 ,a unique advantage of the ,howard-,smith machine is that it is ball-bearing throughout4 ,the main driving shaft revolves on four massive ball-bearings in case 7#ga74 ,the pullies are firmly fixed to the driving shaft with keys or feathers4 ,afterwards the pullies are machined1 so that the whole shaft with its pullies is perfectly balanced1 and the machine runs smoothly without vibration4 ,the bladed cylinder is likewise mounted on four ball-bearings4 ,the intermediate driving shaft 7#gj71 which is mounted on two ball-bearings1 is connected with a large drum shaft 7#gj;a7 which1 in its turn1 sets the carborundum wheel in motion4 ,illustration3 ,,fig4 #ab ,,shaving-,,machine 7,haley7 ,fig4 #ab represents another make of shaving machine4 ,,chapter ,v ,,preparation ,,of ,,hides ,,and ,,skins ,,for ,,tanning ,before beginning a description of manufacturing processes1 a precise definition of leather may be given4 ,laymen usually describe leather as hides tanned with bark1 ,since the introduction of modern processes1 however1 this is only partly true4 ,in any case1 the definition is very broad4 ,the primary objects of treating raw hides and skins to produce leather is to make them imputrescible and impart various degrees of pliability4 ,these qualities are essential1 but the simpler the methods used to attain them1 the greater the strength of the leather produced4 ,the number of materials that will produce leather is legion4 ,whereas oak bark was almost exclusively used for tanning until the last century1 there are now at least twenty useful vegetable tanning materials4 ,the active ingredient of all of these materials is tannin1 a colloidal or uncrystallisable substance4 ,correctly speaking1 the term tanning1 used to designate the process of converting hides into leather1 should be confined to the use of vegetable tannins2 unfortunately1 the trade has largely adopted the word in many other processes of making leather4 ,for example1 large quantities of leather are produced by the use of minerals1 and especially of chrome salts2 where the latter is used1 the leather is said to be chrome-tanned1 although chromed would be a more accurate definition4 ,one mineral process of making leather1 namely1 that involving the use of alum1 or alumina sulphate1 and salt1 is technically described as tawing1 ,the conversion of skins into leather by the use of oxidised oil is known as chamoising1 imitation chamois leather being made by that process4 ,nearly every mineral has the property of converting skins into leather1 though most of them are of little practical value4 ,the most successful are the chrome salts1 and alum and salt4 ,the use of iron salts would be by far the cheapest process1 if means could be found whereby they could be successfully used4 ,sixty years ago1 a chemist named ,knapp experimented with iron salts1 but failed to produce satisfactory leather4 ,patents were taken out in ,austria in the early part of #aiad for the use of iron salts in tanning1 while a patent of more recent date covers the use of iron salts in combination with chrome salts4 ,neither of these appears to be of much practical value4 ,the cheapest and most stable iron salts1 the sulphate and chloride1 have strongly acidic properties1 and1 therefore1 have a somewhat destructive and hardening effect on animal fibres4 ,the iron salt that might convert skins into leather is the carbonate1 which is difficult to prepare cheaply enough for commercial purposes1 though it is used medicinally4 ,a basic iron salt might also be useful1 but iron tannages would only be suitable for black leather4 ,oils and fats also have leather-making properties1 fish oils being used for the manufacture of chamois and antelope leather4 ,there are other methods of producing leather which are not used on a large scale1 but sufficient examples have been given to show that an exact definition of leather cannot be summed up in one or two words4 ,there are now many kinds of leather produced by varying methods1 and each class requires its own definition4 ,broadly speaking1 however1 leather is an imputrescible material produced from the raw skins of animals1 chiefly of cattle1 sheep1 and goats1 by treating them with tannins extracted from the barks1 wood1 fruit1 or leaves of trees2 or with chemicals 7chiefly chrome salts1 or alum and common salt72 or with oils and fats4 ,the preliminary processes are of great importance1 as they determine to a large extent the character of the finished leather4 ,mistakes made in the early processes can never be effectually remedied4 ,the first operation is technically known as soaking1 and its object is to cleanse the hides or skins thoroughly4 ,this is quite simple in the case of raw hides received direct from the slaughterhouse1 as it is merely a question of soaking them in clean1 soft water for a few hours4 ,if the only water available is hard1 #a_/b lb4 of borax should be added for every #ajj lb4 of raw hides4 ,borax is useful in any case1 as it is a splendid cleanser and a very useful chemical in the tannery4 ,most of the hides used in the ,united ,kingdom1 however1 are wet-salted 7i4e41 salted in the wet state71 as it has become customary for most butchers to send hides and skins to the auction markets in all the principal towns1 where they are offered for sale every week4 ,it is still a debatable point among tanners as to whether it is better to buy hides direct from the butcher or through these markets4 ,it is certainly a great advantage to put hides into work quickly 7although not before they are quite cool71 as time is saved in the soaking process1 and there is practically no loss of gelatinous matter4 ,on the other hand1 the tanner is able to buy just the selection of hides that he wants from the auction markets4 ,under this arrangement1 several days must elapse before the tanner receives them1 and it is1 therefore1 absolutely necessary to preserve them1 otherwise they begin to decompose quickly4 ,the first sign of decay is the slipping of the hair1 which1 in that condition1 may be pulled out of its roots quite easily4 ,micro-organisms multiply rapidly in the gelatine of the hide1 the grain comes away1 and decomposition sets in so quickly that1 in a few days after the removal of the hide from the carcase1 it may lose nearly half its value for tanning purposes if it has not been preserved by salting or by drying rapidly in the shade in a current of air4 ,salted hides need a more prolonged soaking than fresh hides1 as it is essential that all trace of salt be removed before the next process1 otherwise the finished leather may be flat1 and poor in quality4 ,usually1 two days' soaking in several changes of water is necessary4 ,for the soaking process1 fresh or salted hides and skins are either soaked in square1 cement-lined1 brick pits1 or in wooden vats filled with clean1 cold water4 ,a good system is to put a pack of skins in one huge tank filled with clean water and leave them in soak overnight before transferring them to the ordinary pits4 ,each pit will take #ej hides1 or #aj dozen calf skins1 or #bj dozen goat skins4 ,tanners designate as a pack each lot of hides or skins they work through1 irrespective of the quantity4 ,illustration3 ,,fig4 #ac ,,drum ,,tumbler ,illustration3 ,,fig4 #ad ,,faller ,,stocks ,besides salting them1 there are other ways of curing hides and skins1 and a large proportion is simply dried or dry-salted1 the salt in the latter method being applied while the hides are moist4 ,dry hides1 whether flint 7i4e41 simply dried7 or salted1 require special treatment to make them soft and pliable1 without which it would be impossible to convert them into leather4 ,soaking in plain water is insufficient1 as it would need too much time1 during which there would be a great loss of gelatine4 ,the use of chemicals and mechanical motion are required2 sometimes chemicals alone will thoroughly soften the hides1 but this is not often the case4 ,both alkalies and acids may be used for softening dried hides1 and it is difficult to say which gives the better result1 although the former are frequently used1 mainly because treatment with acids is a comparatively recent innovation4 ,both kinds are effective1 but the use of acids retards the loosening of the hair1 although it has been proved experimentally that acid-softened hides give a slightly improved yield of leather compared with the effect of the alkaline process--a noteworthy advantage where the finished leather is to be sold by weight4 ,the acid generally used--formic--has antiseptic properties1 and can have no harmful effect on animal tissues1 as is generally the case where mineral acids1 especially sulphuric1 are used4 ,sulphurous acid is also said to be a good softening agent for hides1 but it is rarely used4 ,the most satisfactory alkalies are sulphide of sodium 7crystallised or concentrated7 and caustic soda1 and of these two1 the sulphide is preferred in nine cases out of ten4 ,the quantities used vary according to the condition of the hides1 but the average is about #a lb4 of caustic soda1 or #a lb4 of concentrated sulphide of sodium 7#fe per cent471 or #b lb4 of crystallised sulphide of sodium 7#cj per cent47 for every #ajj gal4 of water4 ,of formic acid1 #a lb4 is sufficient for #ajj gal4 of water4 ,it is possible to soften hides by these means without mechanical acid1 but the time is considerably shortened by drumming the hides1 i4e41 placing them in a round or1 preferably1 a square tumbler fitted inside with shelves or staves 7,fig4 #ac74 ,the drum is rotated mechanically for a few hours1 during which time the hides are thoroughly kneaded and softened by the alkali4 ,tanners often use a machine known as the faller stocks 7,fig4 #ad71 which kneads the hides very thoroughly1 though somewhat drastically4 ,the drum method is preferable1 providing the hides can be suitably softened4 ,an old method1 and one that is used now by some of the small firms1 is to break over 7i4e41 vigorously scrape7 the hides with a curved blunt knife fitted into two wooden handles4 ,for this manual operation1 the hide is placed1 flesh side up1 over the tanner's beam 7,fig4 #ae7 and is then scraped with the knife4 ,illustration3 ,,fig4 #ae ,,tanner',s ,,beam ,another old method1 which has not yet disappeared1 is to make use of stale soak liquors1 which1 although efficient for softening purposes1 cause a great loss of hide substance owing to the active growth of bacteria1 which are developed as a result of the water becoming foul and putrid with dirt1 blood1 and dissolved gelatinous matter4 ,this method of soaking is always dangerous1 apart from the great loss of gelatine1 for the thin grain 7hyaline layer7 is liable to be eaten away in patches1 a defect which greatly reduces the value of leather4 ,dried hides are not only difficult to treat successfully in the different processes of making them into leather1 but they are also of highly speculative value1 although they are well preserved when completely dry4 ,it sometimes happens1 however1 that the drying is imperfect2 it may1 for example1 have been so rapid that the exterior of both sides is thoroughly dried before the air is able to penetrate into the centre4 ,the result is that the interior of the hide putrefies1 but there may be no indication of this until the hides are soaked and softened1 when they may fall to pieces and are only saleable to glue makers4 ,again1 the hides may be dried in the hot sun and be badly blistered1 with the same result as regards their value for leather4 ,if the hides are dried in too high a temperature1 they become horny and rarely make satisfactory leather owing to the difficulty of softening them4 ,it is estimated that quite #aj per cent4 of the dried hides are improperly cured and1 therefore1 useless for making into satisfactory leather4 ,apart from the commercial risk in buying dry hides1 their import1 especially from ,russia and ,china1 is a source of danger in conveying the disease of anthrax to workmen4 ,it has been conclusively proved that dried hides are much more liable than wet-salted hides to cause infection4 ,so far1 only one country1 the ,united ,states of ,america1 has taken steps to prevent the importation of the disease of anthrax1 although most countries have issued regulations in regard to the precaution to be taken to avoid infection by anthrax in those factories where imported hides1 wool1 hair1 and bones are treated4 ,it would seem that the most rational method would be to disinfect the hides before they are shipped1 as it certainly appears to be unwise to import any form of disease2 unfortunately1 the first regulations issued by the ,american ,government proved to be impracticable1 as the suggested method had the effect of lowering the quality of the hides1 and making the preliminary operations troublesome4 ,their second scheme1 consisting of baling a certain number of hides in canvas disinfected with a #j4jb per cent4 solution of mercuric chloride1 is more satisfactory1 for1 although it may not sterilise all the anthrax spores inside the bale1 it should prevent them reaching other goods4 ,this ,government order only applies to hides1 skins1 hair1 and wool coming from countries where anthrax is known to be prevalent4 ,the disease of anthrax is generally contracted by workers through sores or cuts in the hand2 the bacilli multiply rapidly in contact with the blood1 and the first sign of disease is usually shown by a red swelling or pimple in the neck4 ,if treated at this stage by anti-anthrax serum a cure is often effected1 but if treatment is delayed the disease quickly proves fatal1 the patient dying in awful agony4 ,the germs of the disease may also be swallowed and the disease develop internally1 but cases of this kind are rare4 ,besides the danger to workers1 there is the risk of cattle being infected4 ,the effluent from tanneries where anthrax-infected skins are treated contains millions of bacilli1 and it is doubtful if the latter are sterilised even when the effluents are precipitated and arated before they are run into streams or municipal sewers4 ,in any case1 the sediment may be infected1 and this ultimately finds its way to the land4 ,until the various ,european ,governments insist on imported hides from anthrax-infected areas being sterilised before shipment1 the use of a disinfectant such as lysol or a similar cresylic compound1 or bichloride of mercury1 seems imperative in the first process of soaking4 ,the use of these disinfectants would make the waste liquors fit for discharge into sewers or streams4 ,the ,english ,public ,health and ,river ,pollution ,acts have had a great effect in improving the hygiene of the tannery1 although leather manufacturers have not welcomed them1 as1 in some cases1 they have meant considerable expense in providing settling tanks for the treatment of waste liquors4 ,the ,public ,health ,act gives power to any town corporation to declare as offensive trades such businesses as tanning1 hide and skin merchanting1 fellmongering1 tallow melting1 etc41 and several boroughs have taken advantage of this law4 ,in such cases1 anyone desiring to set up business in these trades must apply to the ,town ,council1 who may or may not give their consent2 in fact1 a few applications to establish these businesses have lately been refused4 ,while the curing of wet hides with salt or in brine is more satisfactory than drying them1 the use of ordinary salt is not an ideal method1 as #aj per cent4 brine dissolves hide substance4 ,the recent introduction of a pure dry salt 7#ii-ih per cent47 and of a sterilised salt for commercial purposes has to a large extent removed the objections to ordinary salt4 ,dry sulphate of soda is also a satisfactory cure4 ,it may be that1 as hygienic conditions are further advanced in the various industries1 a suitable disinfectant will have to be used for all hides1 in addition to the salt1 except where the hides are sent direct to the tannery from the slaughterhouse4 ,the cure of hides in hot countries1 especially where cheap salt is unavailable1 is often unsatisfactory4 ,a method of obviating this difficulty has been found in ,china1 where1 in one or two of the principal towns1 hides and skins are preserved by freezing them in cold-storage4 ,although this process stiffens the hides1 it is said to be fairly satisfactory if they are allowed to soften naturally before soaking them4 ,if submitted to rough treatment before the stiffness relaxes1 there is a great danger of the hide fibres being ruptured4 ,freezing removes the difficulty of softening which is experienced in treating dried hides1 while it preserves the hide substance4 ,after the operation of soaking1 hides and skins are ready to be treated for the removal of the hair4 ,there are several ways of loosening the hair sheaths1 but most of them consist of treating the hides in a solution of a caustic alkali4 ,the use of a solution of common lime was practically universal until a few years ago1 but nowadays sulphide of sodium1 red arsenic sulphide 7realgar71 and caustic soda are also used1 generally in admixture with the lime4 ,another process consists in sweating the hides in a heated room1 preferably a damp cellar1 where rapid decomposition of the hides soon loosens the hair4 ,this method is rarely used in ,england1 but a few ,american tanners seem to prefer it for certain classes of hides4 ,in the ,american process1 the hides are first soaked1 and then cut in half down the back1 forming what are known as sides4 ,dry hides are subjected to the usual mechanical operations in the faller stocks1 in which they are kneaded by two large hammers 7,fig4 #ad71 or they are drummed in the tumbler 7,fig4 #ac74 ,after the sides are thoroughly softened and drained1 they are transferred to the sweat pit1 which is1 preferably1 a dark underground chamber4 ,the stock requires very careful attention as the process is risky4 ,the temperature should never exceed #ge ,f41 otherwise the hides may be irretrievably ruined4 ,the process may take from one to four days1 according to the varying conditions of the hides and of the weather4 ,the loss of nitrogenous matter gives rise to the development of a strong odour of ammonia1 which is sometimes even too pungent for the workmen4 ,when the hair is judged to be sufficiently loose1 the sides are washed in cold water and put in the stocks again for about ten minutes1 when all the hair will be removed2 or the hair may be scraped off in the unhairing machine4 ,this method is not useful for sole leather1 as it causes too great a loss of gelatine1 but it saves time in the production of sides intended for boot upper leather1 which is usually sold by measurement 7superficial area74 ,a dehairing process has lately been invented and patented1 however1 which may supersede all of the methods just described4 ,this process consists in treating the hides with various enzymes which loosen the hair so effectively that it can be removed more easily than the hair of a limed hide4 ,the fine1 short hairs underneath are also removed1 whereas by the lime method a further process is needed to get rid of these hairs4 ,the only drawback to its use is that the inventor has not yet been able to produce a material cheap enough to place on the market1 but as soon as this difficulty is overcome the enzyme method may become fairly general4 ,neither the hair nor the gelatine of the hide can be damaged by this method4 ,illustration3 ,,fig4 #af ,,lime ,,yard 7,dri-ped ,tannery7 ,the usual method of liming is carried out in brick pits of square or rectangular shape with a sloping front on which the hides or skins can be piled to drain 7,fig4 #af74 ,there is a great variation in the quality of lime1 and in all cases it should be tested for the available percentage of caustic lime4 ,a good sample should contain between #gj and #hj per cent4 of pure lime4 ,buxton lime1 which can be obtained in powdered form1 is particularly suitable for the tannery4 ,the ordinary lime is preferable to the chalk lime1 as it is usually stronger1 though it sometimes contains more impurities4 ,gas lime is the poorest of all4 ,lime should be stored in a dark place1 otherwise the outside of the heap carbonates quickly1 forming chalk 7,ca,o ,,co#b ,ca,c,o#c7 which is of no use for the liming process4 ,to prepare the lime for the pits it is slaked 7i4e41 formed into a paste with water4 ,all the lumps should be reduced to paste in order to avoid lime burns1 which are caused by direct contact of the hides with pieces of unslaked lime4 ,a certain quantity of the paste is then added to the water or old lime liquor in the pit1 and the liquor is well plunged up to hasten solution and diffusion of the lime4 ,a long wooden pole1 with a flat block of wood attached1 is used for this purpose and also for pressing down the hides under the surface of the liquor4 ,two methods of liming are in vogue3 7#a7 the single-pit system1 and 7#b7 the three-pit system2 but the latter is the better method1 as it is more easily controlled1 and causes less loss of gelatine than the former4 ,in this system the liquor is strengthened with fresh lime for each pack of skins4 ,its great fault is that the pit is only cleared out at long intervals in order to take advantage of the mellowness of used lime liquors2 hence1 there is frequently large accumulation of insoluble limestone and other sediment from the lime1 in addition to a quantity of dissolved gelatine1 which rapidly accumulates putrefactive bacteria4 ,when the pit is cleared out the process of liming is disturbed for a time1 as fresh lime liquors are not beneficial to hides and skins1 and the loosening of the hair is delayed4 ,on the other hand1 the three-pit system permits liquors of uniform strength1 and the process is continued without interruption4 ,each new pack is first placed in the oldest of the three liquors1 which is then cleared out1 and a new liquor prepared4 ,from the weakest pit the hides pass to a stronger liquor1 and the process is finished in the third pit1 which should contain a new lime liquor4 ,the mellow liquors1 being charged with bacteria1 facilitate the loosening of the hair1 while the third liquor1 consisting of fresh lime1 serves to swell the fibres of the hide1 by means of which the flesh is more effectually removed4 ,the lime also forms a soap with the natural grease of the hide2 this grease can therefore be removed4 ,in some cases1 however1 especially in the cattle fed up for ,christmas1 the hides contain a larger quantity of fat than the alkali of the lime liquor can convert into a soap1 and the surplus grease is frequently seen in the finished leather1 as it is difficult to remove in later processes4 ,a solution of hyposulphite of soda1 or lactic acid1 given just before the process of tanning is said to remove the grease1 although a slight loss results in the case of those leathers sold by weight4 ,the objection to natural grease in leather can be understood where the latter is intended for colours1 but in the case of sole leather it ought not to be a disadvantage1 yet1 owing merely to the darker appearance of the leather where the grease reaches the grain1 its selling value is reduced by #b;d4 or #c;d4 per lb4 ,the strange part is that the grain of this sole leather1 when made into boots1 is buffed on an emery wheel1 then sometimes coloured with a paint1 and finally sold in boots at the same price as leather free from grease and regular in colour4 ,the liming process in pits takes from six days to a month1 according to the character of the leather required4 ,light calf skins may be ready for unhairing within a week1 while hides intended to be finished for raw hide leather may be left in the pits quite a month1 the object being to distend and harden the fibres4 ,lamb skins intended for parchment1 and small calf skins for vellum1 are also subjected to prolonged liming4 ,between these extremes1 there are several stages in the process which have varying effects on the character of the finished leather4 ,in fact1 it is a tanner's dictum that leather is made or marred in the lime liquor1 though this1 of course1 only applies to a certain extent4 ,generally1 however1 the heavier the hides1 the longer the liming required4 ,fortunately1 the limited solubility of the lime in water affords a wide margin of safety in working1 and the only danger to guard against is the too prolonged use of old liquors1 which are readily detected by the strong odour of ammonia4 ,one important property of lime is its lower solubility in hot than in cold water4 ,lime by itself does not readily attack the hair bulbs1 and the slowness of the process has led to the introduction of other chemicals1 generally for use in conjunction with lime4 ,the principal of these are sulphide of sodium and red arsenic4 ,mixtures of sulphide of sodium and lime1 or red arsenic and lime are now largely used1 the former for hides1 calf1 and sheep skins1 and the latter for goat and kid skins4 ,both sulphide of sodium and arsenic dissolve keratinous matters 7horns1 hair1 etc47 and workmen should1 therefore1 be provided with rubber gloves to prevent the loss of their finger nails4 ,sulphides naturally lower the commercial value of the hair removed and1 if used alone1 destroy it4 ,in admixture1 however1 the hair has some value1 although it is not so good as that removed by the use of pure lime4 ,against this1 however1 there is a great saving of time and less loss of hide substance and1 therefore1 increased weight of leather4 ,sulphide of sodium is prepared in crystallised or concentrated form2 the former1 about #cj per cent4 strength1 is preferred in ,great ,britain1 while the latter--#fe per cent4 strength--is prepared for export1 the main object being to save the cost of transit of #ce per cent4 of water4 ,about thirty different sulphide salts may be used1 but the sodium and arsenic disulphides are the best1 as it has been shown that the most rapid loosening of the hair occurs where the quantities of sulphur and alkali are nearly the same4 ,there are two arsenic salts used in the trade1 namely1 realgar1 or red sulphide of arsenic 7,as#b,s#b7 and orpiment1 or the yellow sulphide 7,as#b,s#c71 but the former is often preferred as it is said to give better results than the latter4 ,in practice1 the proportion of arsenic used is #a part in #bj parts of lime1 although it naturally varies a little according to the class of skin under treatment4 ,sulphide of sodium is used in the proportion of #a part to #aj of lime1 or1 if concentrated sulphide be used1 #a in #bj4 ,the quantities of lime1 or lime and sulphide1 used are estimated on the weight of the raw hides4 ,for hides intended for sole leather1 #e per cent4 of lime on the weight of hides is ample1 while a little more may be used for hides intended for dressing leather 7i4e41 leather which has to be dressed or finished with a certain degree of flexibility for bags1 boot uppers1 etc474 ,when a mixture of lime and sulphide is used1 #c per cent4 and #j4c per cent4 respectively is a satisfactory quantity4 ,the action of this mixture on hides is complex and has not yet been definitely ascertained1 but it is thought that the calcium sulphydrate formed by the chemical reaction between sulphide of sodium and calcium hydrate 7slaked lime7 is the active principle4 ,in the pit method of liming1 it is essential that the liquors be frequently plunged1 while the hides should be taken out 7hauled71 piled to drain for a few hours1 and put back again 7set71 or transferred to another pit4 ,although lime is more soluble in cold than in warm water1 it is found in practice that the process may be stopped or considerably retarded in very cold weather1 and the activity of the liquors is increased by the application of waste steam 7conveyed through iron pipes from the boiler74 ,sulphide of sodium and lime are sometimes made into a thin paste1 which is applied to the hair side of hides and skins with a mop or fibre brush4 ,the hides are then folded down the back with the flesh sides out2 other hides are similarly treated and placed in a pile4 ,this saves a great amount of labour in pitting1 and1 if the paste is fairly strong1 consisting of #b to #b-a_/b per cent4 sulphide1 the hair can be removed after a few hours4 ,with so many depilatories available1 it is not surprising that several patents have been granted and numerous suggestions made with the object of trying to improve on the old process of liming4 ,while there may be some objections to lime1 it has a few advantages which are lacking in other depilatories4 ,these advantages are not perfectly understood theoretically1 but the tanner recognises them in practice4 ,hence1 there are very few tanneries where lime is not used at all1 and the only progress that seems to have been made in the process of liming consists in the admixture of sulphide of sodium or arsenic to hasten the process1 reduce the loss of gelatine1 and1 in the case of arsenic1 to improve the fineness of the grain of skins for boot upper and glove leathers4 ,one patented method consisted in forming the calcium hydrate within the hide by treating it with a #a per cent4 solution of caustic soda and then with a #a-a_/b per cent4 solution of calcium chloride1 the reaction of these two chemicals forming calcium hydrate 7lime7 and sodium chloride 7salt74 ,this method1 however1 does not loosen the hair at all and has to be supplemented by soaking the hides in putrid water4 ,it is a good method of liming hides or skins dressed in the hair1 as it opens up the fibres without weakening the hair roots and prepares the hides in a suitable condition for tanning4 ,another method consists in mixing a small quantity of soda ash with the lime1 thereby hastening the process by increasing the alkalinity of the liquor4 ,a somewhat complicated method was introduced a few years ago1 but1 although it seemed advantageous from a chemical point of view1 it has not proved successful in practice so far as is known1 probably because of its expense4 ,in consisted of four distinct processes4 ,the hides were first mopped on the hair side with a thin paste of lime and arsenic1 and dehaired after twenty-four hours4 ,in the second process1 they were treated in a drum for twenty-four hours with a solution of sodium sulphide1 they were then drummed for twenty-four hours in a solution of hyposulphite of soda1 and finally placed in a vat or pit containing a solution of lime and a little arsenic for two to five days4 ,after washing1 etc41 they were ready for tanning4 ,the sulphide of sodium swelled the hides or skins by distending the fibres1 and the natural fat is converted into a soluble soap4 ,the hyposulphite arrests the action of the sulphide and acts as an antiseptic4 ,in modern yards it is a growing practice to use mechanical power to keep the hides in motion1 instead of handling them4 ,the hides are attached to poles joined to a strong cross beam1 which1 in its turn1 is connected by stout iron rods with the main pullies and shafting4 ,the installation is expensive1 but it saves an enormous amount of manual labour and time1 while ensuring uniform treatment4 ,this method is not so much used for liming as for the tanning process4 ,after loosening the hair and opening up the fibres1 the next operation is dehairing or depilation1 or1 as it is generally described in the trade1 unhairing4 ,the hair must slip quite easily before beginning this operation1 otherwise a number of them will be left in the hide and will be difficult1 or almost impossible1 to remove later on if the hides are being made into sole leather4 ,these hairs present an unsightly appearance and lower the value of the leather4 ,depilation may be done by hand or machine2 but the latter method is rapidly superseding the former1 as it is in nearly every other process of leather manufacture4 ,in the manual process1 the hair is removed by scraping it off in a downward direction with a blunt1 convex-shaped knife1 fitted into two wooden handles 7,fig4 #ag71 the hides being placed on a sloping convex beam 7,fig4 #ae7 supported by a trestle4 ,a series of grooves under the beam permits it to be placed at any angle4 ,the beam 7different from that used by curriers7 may be of wood1 iron1 steel1 or zinc-covered wood4 ,illustration3 ,,fig4 #ag ,,dehairing ,,knife ,there are several types of unhairing machines1 of which the ,leidgen more nearly approaches hand work than any other4 ,the skins are placed on a soft bed of felt1 and the working roller1 fitted with spiral knives1 is brought into contact with the hide and scrapes off the hair4 ,illustration3 ,,fig4 #ah ,,dehairing ,,and ,,fleshing ,,machine ,the type of machine often used1 however1 is shown in ,figure #ah2 the working part is a long spindle fitted with helical knives4 ,the advantages of this machine are its large output and its use for other operations by simply changing the working roller4 ,the blades must be blunt for dehairing1 but sharpened blades are needed for fleshing4 ,if hides intended for sole leather are being dehaired1 the short hairs which are not removed by the dehairing knife are carefully scraped off with a sharp knife4 ,other kinds of hides and skins are freed from short hairs in a later operation4 ,when the hides are dehaired1 they are sometimes submitted at once to the next operation of fleshing1 which1 as its name implies1 consists in removing loose flesh and fat from the flesh side1 that is1 the side near the carcase4 ,the extent to which this operation is carried out depends on the quality of the finished leather4 ,naturally1 the more flesh left on the greater the weight1 particularly as loose flesh will absorb a large quantity of tannin1 and1 unfortunately1 of adulterants which are frequently used for weighting common leathers4 ,the flesh ought to be removed in all cases1 for the loose flesh forms very poor and spongy leather4 ,where hides and skins are tanned and then dried for sale to leather dressers and finishers1 there is often the tendency to leave far too much loose flesh on them1 with the object of producing as much weight of leather as possible4 ,from the point of view of economy1 this is a mistake1 for the loose flesh must be removed during the dressing process1 whereas1 if it had been taken off at first1 both material and time would have been saved in the process of tanning4 ,if the fleshing is not done directly after dehairing1 the hides or skins should be placed in a weak lime liquor1 and this method is to be recommended4 ,the great point to be observed is to keep the limed hides1 both before and after dehairing1 away from contact with the air1 as the chemical action of the carbonic acid on lime results in the formation of chalk1 which tends to harden the hides and to roughen the grain1 so that it is likely to be scratched in later operations4 ,where the hides are intended for sole leather1 and not treated with an acid before entering the tanning liquors1 the presence of chalk would lead to an uneven colouring of the leather4 ,illustration3 ,,fig4 #ai ,,fleshing ,,knife ,fleshing by hand demands great skill4 ,the knife used 7,fig4 #ai7 is similar to the unhairing knife1 except that it has two edges4 ,the cutting is done with the convex edge1 which has to be kept very sharp4 ,the concave edge need not be sharp1 its use being limited to scraping off loose particles of flesh1 while the parts not removed by this means are cut off with the sharp edge4 ,the knife is held slantingly1 with the blade almost parallel with the beam4 ,the strokes should be short and in a semicircular direction1 otherwise it is difficult to avoid cutting the skins4 ,this manual operation is now largely superseded by machinery1 and will1 no doubt1 soon be obsolete4 ,the early types of fleshing machines were not a success1 but the modern machine is very effective4 ,there are several makes on the market1 but in most cases the working tool is of similar construction and consists of a long cylinder to which spiral knives are fixed4 7,fig4 #ah47 ,half of these blades converge to the left and half to the right1 the object being not only to cut away the flesh but also to stretch the hides outward1 thus ensuring an evenly cut surface4 ,the fleshings and useless pieces of skin are kept in a weak lime liquor until there is a sufficient quantity to send to the glue maker2 although in some of the larger tanneries this offal1 technically termed spetches1 or glue pieces1 is converted into glue on the premises4 ,in hot weather1 a large accumulation of fleshings is liable to putrefaction1 despite the use of plenty of lime water4 ,while lime certainly arrests putrefaction of gelatinous matter for a time1 decomposition afterwards sets in and serious damage may be done4 ,to avoid this1 it has been a common practice in ,germany to use formaldehyde1 but1 while this acts as a preservative1 it hardens animal tissues1 and has a tanning effect1 with the result that the pieces are rendered insoluble and cannot1 of course1 be reduced to a liquid gelatine by boiling4 ,glue makers have condemned the use of formaldehyde1 but other preservatives1 such as lysol 7a cresylic compound7 and arasol1 have no tanning effect and may be used with safety4 ,after the operation of fleshing1 it is necessary to get rid of the lime in the hides1 for1 if they were put directly into tan liquors1 the lime1 being alkaline1 would neutralise the acidity of the tan liquors and retard the beginning of the tanning process for a long period4 ,the leather would ultimately be poor1 thin1 stained1 and brittle4 ,up to the process of deliming1 there is not a great deal of difference in preparing the hides and skins for the large variety of leathers1 but between the fleshing and the tanning processes the work varies considerably1 and largely determines the character of the finished leather4 ,when the hides or skins are in the limed state1 they are gristly and firm in texture4 ,a certain amount of this firmness is desirable in some leathers1 such as sole and belting1 and1 therefore1 it is deemed advisable to leave a small quantity of lime in the hides1 although1 to get them evenly coloured in tanning1 it is essential that the lime should be completely removed from the surface of the hide4 ,an old method1 which is even in use to-day in some tanneries1 is to wash the fleshed hides in a cubical or hexagonal drum for several hours in running water1 which is conveyed through an iron pipe in the journal of the drum1 and escapes through small holes in the drum4 ,the effect of using a hard water for washing out the lime is shown in the interior of these washing drums1 the sides of which become incrustrated with a thick1 hard deposit4 ,the surface of this incrustration is irregular1 and small projections are sometimes formed which mark the hides and reduce their value1 as the impressions are not removed in later processes4 ,the modern method of deliming hides intended for sole leather is to use a weak solution of acid1 or an acid salt4 ,for this purpose1 sulphuric and hydrochloric acids are by far the cheapest1 but require handling with great care1 as any excess used has a corrosive and destructive effect on the fibres1 which results in weak leather4 ,mild organic acids are much safer1 and those generally preferred are lactic1 formic1 and butyric1 although boracic and acetic acids are favoured by some tanners4 ,butyrate of ammonia is used for the same purpose by a number of ,french tanners4 ,the same acid bath can be used for a second lot of hides1 but sufficient acid should be added to raise the acidity of the liquor to its former standard4 ,it is inadvisable to use one bath more than four or five times4 ,the salt formed during the process by the combination of the lime with the acid--calcium lactate1 formate1 butyrate1 acetate1 or borate1 according to the acid used--must be washed from the hides1 either in a pit or drum1 before they are ready for the tan liquors4 ,illustration3 ,,fig4 #bj ,,scudding ,,knife ,other kinds of hides and skins require additional treatment1 according to the class of leather it is intended to make4 ,hides to be dressed for such purposes as bags1 portmanteaus1 cases1 harness1 belting1 and stout uppers are usually steeped in an infusion of hen or pigeon dung4 ,a vat is filled with tepid water1 a quantity of the dung1 usually about half a pailful1 is added and well stirred in the water before putting the hides in4 ,the acid fermentation evolved neutralises the lime1 while bacteria multiply and rapidly reduce the rubbery limed hide to a soft1 flaccid condition4 ,the hides are then well washed in clear water and scudded1 after which they are transferred to the tan pits4 ,scudding is the technical name of an operation performed on hides and skins with a special tool1 known as the scudding knife1 which consists of a convex piece of slate or vulcanite fitted into a wooden or steel handle 7,fig4 #bj74 ,the hides are placed on the beam1 grain side up1 and vigorously worked with the knife to scrape off scud 7i4e41 short hairs1 dirt1 and soluble lime salts74 ,both sides of the hides should be scudded for best work4 ,the process of treating hides with excrement is known technically as bating1 ,calf skins1 which are curried or dressed after tanning1 should be reduced to a more supple condition than hides intended for harness1 belting1 and military leathers4 ,a more active dung is1 therefore1 used for skins of all kinds which have to be rendered supple4 ,dog manure is generally used1 that from the hunting kennels being preferred4 ,imported dry dung has to be used by some firms1 as the supply of fresh dung is insufficient4 ,the demand for the latter is very keen1 as it is more effective than the dry product4 ,goat skins dressed for the famous shoe leather known as glazed or glac kid1 and kid skins for glove leather1 need a larger proportion of puer than nearly every other kind of leather1 for the grain of goat skins is naturally hard and requires a large quantity of dung to reduce it to the necessary softness and suppleness of kid leather4 ,although these processes can only be described as disagreeable1 they apparently have no injurious effect on the workmen4 ,further1 the hides and skins are thoroughly cleaned before putting them in the tan liquors1 in which the bacterial activity caused by the infusion of dung is quickly arrested4 ,fortunately1 from the hygienic point of view1 the use of natural bates and puers1 although still extensive1 is likely to be superseded everywhere by artificial products4 ,so far there are nearly #b1jjj tanneries throughout the world where the artificial bating materials are preferred1 ,german and ,american tanners being the principal users4 ,the best known artificial bate is ,oropon1 which consists of a mixture of pancreatin or trypsin1 ammonium salts1 and a large quantity of sawdust1 the last-named merely acting as a mechanical agent4 ,the enzyme1 pancreatin1 is the active ingredient1 and may be prepared from the intestines of the pig4 ,it has the effect of breaking up the albuminous matters of hides and skins1 which are rapidly reduced to a soft and supple condition1 while the ammonium salts cleanse them4 ,the quantities used vary according to the degree of suppleness required in the finished leather4 ,the patentee and vendor of this proprietary article claims that it is suitable for all classes of leather4 ,hides for sole leather are sometimes treated with a weak ,oropon liquor in ,continental tanneries and1 as a result of the cleansing properties of this bating material and its effect in opening up the fibres1 the tannage proceeds rapidly4 ,the use of enzymes for bating was discovered by an ,english leather manufacturer and chemist1 who did not take out a patent for his invention1 probably because he had previously patented and worked on a commercial scale a bacterial bate which gives very good results but requires much skill in application4 ,the artificial product1 ,oropon1 has many advantages over excrements4 ,it is simpler1 cleaner1 and more rapid in working1 and never damages the grain of the skin4 ,on the contrary1 great care and experience are needed in using excrements1 and the skins may be so badly damaged through negligence as to be almost worthless4 ,bate burns are fairly frequent when dung is used1 and are generally due to hard pieces being insufficiently broken up and diffused in the liquor4 ,other useful artificial products are3 ,erodin1 and ,puerine1 a patented ,american product which consists of a weak organic acid and a small proportion of molasses4 ,possibly1 malt enzymes or diastase could be utilised for the manufacture of an artificial bate or puer1 although they would not be so effective as animal products4 ,where hides and skins have been treated with ,oropon1 they may be transferred to the tan liquors after being rinsed in water1 although it is better to submit them to the operation of scudding4 ,there are two tests to determine the end of the process of bating and puering1 although the extent to which the reduction is carried depends on the kind of leather wanted4 ,for this reason1 it is not advisable to remove every trace of lime from hides which must possess a certain degree of firmness when finished into leather4 ,of the two tests1 one is chemical and the other mechanical4 ,in the former case1 a cross section is made in the thickest part of the hide and a few drops of phenolphthalein are added to the cross section2 if the whole of the lime has been removed1 no coloration is given1 but1 if lime be present1 a purplish colour is given1 which varies in intensity according to the contents of lime in the hide4 ,the other test is made by pressure with the thumb nail1 and1 if the impression be permanent1 the hides or skins are in a sufficiently reduced1 or1 as it is technically known1 fallen condition for all practical purposes4 ,the latter test is really only useful when the process has to be carried to its fullest practical extent1 as it affords no idea of the intermediate stage4 ,the experienced workman can judge the progress made by appearance and touch4 ,in cases where skins have been puered with excrement it is often necessary1 after scudding them1 to submit them to a further process before tanning4 ,this is known as drenching1 and consists in treating the skins in an infusion of wheaten bran or pea flour4 ,the acid fermentation produced by these ingredients effectually cleanses the skins by neutralising the last traces of lime and scud1 and prepares them in an ideal condition for the process of tanning4 ,the combined processes of bating with ,oropon and drenching in bran are extremely useful for skins to be dressed into glove leather4 ,following the processes of bating1 puering1 or drenching1 the skins are washed in water to remove all mechanical impurities1 and are then in a perfectly clean condition for tanning4 ,,chapter ,,vi ,,tanning ,,processes ,the methods of tanning may be classified as follow3 7#a7 ,vegetable tanning processes2 7#b7 methods of chroming2 7#c7 tawing processes2 7#d7 oil tannages2 7#e7 formaldehyde tannages2 7#f7 sundry tannages1 chiefly mineral2 and 7#g7 combination tannages4 ,the public is chiefly familiar with types of vegetable tannage in boot sole1 bag1 and portmanteau leathers2 of chrome tannage1 in box calf and glazed kid used for boot uppers2 of the tawing process1 in kid glove leather2 and of the oil tannage in wash leather or chamois4 ,,vegetable ,,tanning ,,processes ,the methods of tanning with infusions of barks1 leaves1 and fruits of trees and plants containing tannin are much more numerous than they were a decade ago1 and tanners have now to pay special attention to the selection and blending of the materials they use in order to produce the various qualities of leather required4 ,formerly1 most of the sole leather was tanned in oak bark liquors1 and1 in the later stages of the process1 valonia and gambier were added to quicken the process and give solidity to the leather4 ,this tannage1 which may be described as an oak bark tannage1 is still used by a few tanners1 but the wide choice of materials available has brought other tanning agents into prominence1 chiefly because they possess more astringent properties1 and1 therefore1 tan more quickly than oak bark4 ,moreover1 the need of other materials than oak bark became a necessity several years ago1 as the supply of the latter would be inadequate to produce the large quantity of leather now required1 even allowing for the rapid development of mineral tannages4 ,further1 it is amply proved that a good blend of materials 7mixed tannage7 produces quite as durable and a firmer leather than the old oak bark tannage2 unfortunately1 there are other blends1 occasionally combined with extraneous weighting materials1 which account for the poor quality of a great deal of modern sole leather4 ,while the mixed tannage is now popular for sole1 belting1 harness1 and other heavy leathers1 vegetable tanned light skins1 such as calf1 goat1 and sheep1 are in most cases treated with a single material1 sumach being used for a good proportion of them4 ,whichever method be used1 the first essential is the most suitable means of leaching the materials1 or extracting the tannin4 ,it seems1 however1 that this process may be eventually eliminated from the tannery1 for most tanning materials are now converted into extracts1 which only require dissolving in water to prepare the tan liquor4 ,the manufacture of tanning extracts is quite a separate business1 which is generally1 but not always1 conducted in factories situated near the source of the raw materials4 ,there are important extract works in the ,argentine1 ,paraguay1 ,canada1 the ,united ,states1 ,hungary1 ,north ,germany1 ,borneo1 ,smyrna1 ,france1 ,italy1 and ,england4 ,illustration3 ,,fig4 #ba ,,bark ,,mill ,where natural tanning materials are used1 either entirely or in conjunction with extracts1 the leaching is done in a series of large square pits1 four of which would suffice for a small yard1 while a very large tanning would need twelve or sixteen4 ,oak bark1 which is usually delivered to the tannery in strips measuring #c to #f ft4 in length1 must be chopped or ground into small pieces by machine 7,fig4 #ba74 ,a measured quantity 7a certain number of baskets or skeps full7 is placed in the empty pits1 which are then filled with water4 ,the liquor is pumped from these pits1 as required1 to others in which the hides are tanned4 ,the hard fruit of myrobalans1 which somewhat resembles nutmegs1 is powdered in a disintegrator or special crusher4 ,illustration3 ,,fig4 #bb ,,tan-,,yard 7,dri-ped ,tannery7 ,illustration3 ,,fig4 #bc ,,hide ,,rounded ,,for ,,sole ,,leather ,the three principal vegetable tannages are those for sole1 dressing1 and light leathers1 and it is obvious that a careful selection of materials is necessary to obtain the desired effects4 ,for this reason1 oak bark1 although a good tanning material for dressing leather1 is insufficient to produce a firm sole leather1 and1 therefore1 even in the so-called pure bark tannages1 valonia or other suitable tannin is used towards the end of the process in order to increase the solidity and waterproof quality of the leather4 ,there are two general methods of tanning sole leather1 namely1 the pit and the drum tannage4 ,in the first case1 the hides are passed through three series of pits containing gradually increased strengths of tannin 7,fig4 #bb74 ,these series are technically described as suspenders or colouring pits1 handlers1 and layers or layaways4 ,to facilitate handling and economise tanning materials1 hides are rounded 7i4e41 cut into sections7 either before tanning or after the hides have passed through the suspenders 7,fig4 #bc74 ,the obvious advantage of the former method is that the offal 7shoulders and bellies7 removed can be chrome tanned if required4 ,the suspenders may consist of any number of pits from six to twenty-four1 according to the size of the tannery4 ,as the name implies1 the hides are suspended in the liquors from poles1 which extend across the top of the pit4 ,the hides are attached to the poles by means of stout cord or copper hooks4 ,various mechanical appliances are in use to supersede the old method of allowing the hides to rest during this process4 ,these methods save time and tend to produce even coloration1 the latter being a very important point in the early stages of tanning4 ,some of the methods advocated1 however1 are too vigorous for the hides at this stage1 when the chief object should be to preserve as much gelatine as possible4 ,the best mechanical system is that which gently raises and lowers the hides in the liquors4 ,some of the ,american tanners use a mechanical contrivance known as the rocker1 which consists of a stout wooden beam rocking from a central pivot1 and with a see-saw movement4 ,the objection to this method is that the hides do not receive equal treatment1 those in the centre receiving hardly any movement1 while others at the ends of the beam are raised too far out of the liquor4 ,under these conditions1 the colouring of the leather must be irregular4 ,another method1 invented in ,england1 consists in suspending the hides from a wooden frame which can be mechanically moved on wheels4 ,as the contact of tanning liquors with iron must be avoided to prevent discoloration 7iron and tannin form the basis of inks71 the wheels should be galvanized4 ,this mechanical method is very satisfactory1 for the hides are moved gently and kept in the liquors4 ,as some tannins oxidise rapidly 7i4e41 darken in colour by exposure to the air71 any process which exposes the hides at this stage for lengthy periods should be avoided4 ,illustration3 ,,fig4 #bd ,,barkometer ,the theory of the vegetable tanning process is not perfectly understood1 and the principal trade chemists are not yet agreed as to whether the changes are chemical1 physical1 or both4 ,many are inclined to believe that both changes take place1 and this view is probably correct1 as a pure tannic acid produces a thin1 empty leather1 while a tanning material which contains a fair proportion of non-tannin matters1 yields a full and firm leather4 ,the practical tanner who adapts his work to the theory that tanning is a process of feeding the hides with gradually increasing strengths of tannin1 is1 in any event1 on the right track4 ,the suspender liquors are always weak in tannin1 and are pumped from handler liquors through which packs of hides have already passed4 ,it is important that these liquors possess a certain degree of acidity1 and1 if the natural acids of the tan liquor are too weak1 or neutralised completely by the lime in a pack of hides that has been treated1 a small quantity of acetic1 formic1 or lactic acid is added4 ,formic acid has the additional advantage of making the liquor antiseptic4 ,it is absolutely necessary that the liquors have acid properties1 otherwise tanning cannot proceed4 ,acid assists penetration of tannin4 ,hyposulphite of soda1 formaldehyde1 or synthetic tannin may be used for the same purpose1 while these also help to keep the leather light in colour1 owing to their bleaching properties4 ,after passing through three or four suspender pits1 in which the tan liquor is gradually strengthened1 the hides are often rounded and the butts 7,fig4 #bc7 are transferred to the handlers4 ,the first handler liquor should register about #be degrees by the barkometer 7,fig4 #bd71 an instrument which registers the density of tan liquors4 ,the handlers consist of a series of six or eight1 and the strength of the liquors should be increased gradually4 ,after a day's immersion in the first handler liquor1 the hides are hauled out with a sharp two-pronged hook fixed to the end of a long wooden pole1 similar to that used in the liming process4 ,after they have been piled up for a few hours1 two workmen1 one on each side of the pit1 place the hides flat in the next pit4 ,the tan liquor is then run off the first handler to the suspender and fresh liquor is pumped into the empty pit1 which then becomes the head or strongest liquor of the series4 ,the succeeding packs will1 therefore1 follow in rotation3 the first going to ,no4 #b pit1 the second to ,no4 #c1 and so on4 ,in the last two or three handler pits1 the hides are sometimes dusted with freshly ground tanning material1 such as oak bark1 myrobalans1 or divi-divi1 the object being to strengthen the tan liquor so that it penetrates the hides before they are transferred to the layers4 ,the handler liquors1 which are originally sent back from the layers1 are also frequently strengthened by the addition of oakwood1 chestnut1 or quebracho extracts1 although some tanners only use extracts in the layers4 ,gambier is a useful material at this stage1 as it keeps the liquors mellow and plumps the leather4 ,in the layers1 the last series of tan pits1 the hides are treated with very strong extracts1 and are also heavily dusted with such natural tanning materials as give firmness and solidity to the leather4 ,for this purpose1 nothing is better than valonia1 or valonia extract1 which deposits a large quantity of bloom1 or ellagic acid4 ,where a mixed tannage of natural materials is used1 the density of the liquors may reach #ej degrees barkometer1 but if strong extracts be added1 the barkometer may exceed #ajj degrees4 ,the relation between the layers and handlers in regard to the disposal of the used liquors is similar to that between handlers and suspenders2 the first layer used is sent to the last handler4 ,by the ,english method1 the leather is not1 as a rule1 transferred immediately from one pit to another1 as it is found preferable to lay the hides in pile for a few hours1 by which means the great weight helps to force the tannin through them4 ,by draining the hides1 they are in good condition for the absorption of the next tan liquor4 ,the ,english method of handling is too slow for most of the ,american tanneries1 where the greater proportion of the hides are cut straight down the centre to form sides1 as they are technically known4 ,in ,america1 the pieces of leather1 whether hides1 butts1 bellies1 or shoulders1 are often tied together and transferred from one pit to another by means of a skeleton reel1 worked either by hand or mechanically4 ,the latest type of reel is a great improvement on the old reel4 ,the cost of manual labour in many ,english tanneries is very great1 in view of the fact that the hides have to pass through many pits1 and the work of transferring the hides from one pit to another is done entirely by hand4 ,it seems that there is plenty of scope for mechanical ingenuity in overcoming this difficulty1 and it may yet be found possible to construct a perforated brass platform1 connected with a crane1 by which the whole of the hides could be lifted out in a second1 left to drain for half an hour or more1 and then bodily transferred to1 and lowered in1 the next pit4 ,naturally1 it is easier1 and quite within the bounds of practicability1 to raise the hides from suspenders by mechanical power1 as it would not be difficult to fix a stout cross-beam to the pulley from which the hides are suspended4 ,the leather can be safely treated with very astringent tannin in the last series of pits1 and the use of strong extracts is1 therefore1 a common practice at that stage1 not only to give solidity and firmness to the leather1 but to increase its weight4 ,it would be quite fatal to the production of good leather if strong tannins were used in the early stages of the process1 because the surface on both sides would tan quickly1 the grain of the hide would be badly drawn owing to the sensitiveness of gelatine to astringent solutions1 and it would be impossible to make the tannin penetrate the hide4 ,the final product would be a half-tanned leather which would be extremely brittle and poor in quality2 in fact1 quite unsuitable for sole leather4 ,despite the well-known axiom that the vegetable tannage 7but not the mineral7 must proceed slowly and gradually in the early stages of the process if the hides are to be properly tanned1 the modern tendency is to speed up the tanning1 with the result that1 in some cases1 the so-called sole leather is really not fit for the purpose for which it is intended4 ,the root of the evil is the desperate attempt made by many boot manufacturers to produce lower-priced boots than those of their competitors4 ,taking into account the development of leather trades chemistry1 it is not surprising that the problem of reducing the time required to complete the old processes of tanning has received much attention4 ,the results have been successful in some instances and have certainly proved that very good sole leather can be made without leaving the hides in the pits for a year or longer4 ,it has also been shown that the absorption of tannin can be accelerated by treating the hides1 before putting them in the suspenders1 with a solution of acid 7lactic or butyric for preference71 or hyposulphite of soda1 or synthetic tannin4 ,the latter penetrates the hides in a few hours without contracting the grain1 increases the solubility of the vegetable tannins subsequently used1 and helps to keep the leather light and uniform in colour4 ,it is of no use alone for heavy leathers1 however1 as it lacks the physical properties necessary to make the leather firm and resistant to water4 ,the use of soluble oils in the tan liquors is another late innovation which has given good results4 ,the term soluble in connection with oils merely means that they are made miscible with water by treating them with acids4 ,solubilised cod oil might be specially useful1 as it has tanning properties and would increase the wearing and waterproof qualities of the leather4 ,the chief objects of using oil in tanning1 however1 are to increase the weight of the leather and permit the use of strong liquors4 ,the tanning process outlined is the oak bark tannage1 which is now supplanted in many yards by the mixed tannage1 in which various tannins1 chiefly exotic1 are skilfully blended to produce the kind of leather wanted4 ,each tannin seems to have special characteristics1 although the materials are classified into only three groups1 namely3 pyrogallol1 catechol1 and mixed 7pyrogallol and catechol7 tannins4 ,generally1 the best mixed tannages for solid leather consist of a combination of both pyrogallol and catechol tannins4 ,reviewing the characteristics of some of the principal tanning materials1 it may be said that oak bark produces a nice1 fawn-coloured leather of strong texture1 but tans slowly2 valonia makes the leather solid1 durable1 and waterproof2 myrobalans quicken the process and lighten the objectionable colour of other tannins2 divi-divi and algarobilla are very rich in tannin1 and are1 therefore1 useful in later stages of the process2 gambier mellows the astringency of other liquors and plumps the leather2 while most of the tanning extracts on the market penetrate the hides much more quickly1 often give a lighter colour than that produced by solutions of the natural materials1 and expedite the process considerably4 ,the most popular tanning materials are3 oakwood1 quebracho1 chestnut1 valonia1 myrobalan1 mangrove1 mimosa1 hemlock and spruce extracts1 oak bark1 valonia1 gambier and sumach4 ,the following are some of the combinations in use-- ,for ,sole ,leather4 #a4 ,oak bark and valonia1 or valonia extract4 #b4 ,oak bark1 valonia1 and gambier4 #c4 ,oak bark1 quebracho extract1 and myrobalan extract4 #d4 ,chestnut1 quebracho and valonia extracts4 #e4 ,chestnut and oakwood extracts4 #f4 ,oakwood and quebracho extracts1 and divi-divi or algarobilla4 #g4 ,quebracho extract1 myrobalans1 and valonia4 #h4 ,quebracho1 mangrove1 and valonia extracts4 #i4 ,oakwood1 mimosa1 and valonia extracts4 #aj4 ,hemlock and oak extracts 7,american union tannage74 ,for ,dressing ,leathers4 #a4 ,oak bark and sumach4 #b4 ,oakwood and quebracho extracts1 and sumach4 #c4 ,synthetic tannin and oakwood extract4 #d4 ,synthetic tannin and myrobalans4 #e4 ,gambier and sumach4 #f4 ,wattle bark and myrobalans4 ,sumach is often used alone for some classes of goat1 sheep1 and calf skins4 ,synthetic tannins can also be used alone for light leathers4 ,many other variations may be tabulated1 for nearly every tanner has his own recipe1 having found by experience the blend of tannage that best suits his trade4 ,apart from these innumerable combinations1 the only method whereby the vegetable tanning process may be hastened is the mechanical1 for which purpose either the paddle 7,fig4 #be7 or the drum 7,fig4 #ac7 is used4 ,the former consists of a wheel constructed of wooden shelves which1 when in motion1 dip a little way into the tan liquor in a vat1 and so keep it in constant circulation4 ,the drum is fitted inside with wooden shelves or pegs1 which carry some of the hides or skins to the top of the drum at each revolution4 ,were it not for these shelves1 the tannage would probably be irregular or otherwise unsatisfactory1 as the hides would always be heaped together at the bottom of the drum4 ,the paddles and drum are more often used for light than for heavy leather1 as they not only have the effect of making the leather loose on the grain1 but also make it soft and supple1 characteristics which are not required in most of the heavy leathers4 ,illustration3 ,,fig4 #be ,,paddle ,,vat ,however1 the drum is now largely used on the ,continent for the tannage of sole leather4 ,a great saving in the cost of production is thereby effected1 but the leather1 although of satisfactory appearance1 lacks the durability and waterproof quality of pit-tanned leather4 ,the process is much simpler than the pit method1 and less room is required4 ,there are only two stages of tanning3 7#a7 by placing the hides in colouring pits or suspenders1 in which the hides are nearly struck through with tannin2 and 7#b7 running them in slowly-revolving drums containing solutions of tannin which are gradually strengthened until the process is finished4 ,there can be no doubt that the tannin is rapidly forced between the fibres of the hide by mechanical action1 but it is not so firmly combined as that slowly absorbed by the hide in the pit method4 ,this can be proved by placing two pieces of weighed leather--one tanned in pits and the other in a drum--for twenty-four hours1 drying the leather and reweighing it1 when it will be found that the drum-tanned leather has lost the greater percentage of weight4 ,to obviate this disadvantage as far as possible1 use is made of special oils1 which serve to fix the tannin more firmly between the fibres and render the leather more resistant to water4 ,other frequent drawbacks of drum tanning are looseness of grain and lack of substance4 ,in sole leather tanning1 the former is modified to some extent by extra pressure in rolling the leather during the finishing operations2 while the latter difficulty is sometimes overcome by swelling the leather with acid and then fixing the swollen condition of the hide by treating it with a weak solution of formaldehyde4 ,this chemical also has tanning properties1 so that the process is hastened2 but leather prepared in this way cannot be as durable as that produced by a natural tannage4 ,it seems that the aid of the engineer is necessary to overcome the difficulty of looseness of the grain caused by the severe pounding of the hides in the drums4 ,the constant circulation of the tan liquor is required1 but the hides should only be subjected to gentle motion4 ,it is true there are tanning drums on the market which are said to obviate all the difficulty found in making sole leather in ordinary drums fitted with shelves or pegs1 but a drum that meets the ideal conditions for the production of a solid yet flexible sole leather has not yet been invented4 ,it seems that a kind of inner framework1 to which the hides can be attached and which rotates much more slowly than the main drum1 may solve the problem4 ,the drum tannage permits the use of an excessive quantity of tannin1 which1 of course1 adds to the weight of the leather4 ,by the drum method of tanning1 heavy hides can be tanned in two days after leaving the colouring pits2 lighter hides are1 naturally1 tanned in less time1 proportionate to their substance4 ,the pit method occupies any time from one to fifteen months1 although nowadays very few hides are left in the tan pits for a year4 ,the methods of tanning just described relate chiefly to sole leather1 but there is an enormous production of leather known as dressing hides1 which are tanned1 dried in the rough state1 and sent to curriers or leather dressers for finishing4 ,these hides are used for numerous purposes1 including bags1 portmanteaus1 harness1 saddlery1 straps1 belting1 and boot uppers4 ,the tannage of dressing hides differs slightly from that of sole leather2 the liquors must be mellower and contain less insoluble matter1 in order to obtain the necessary pliability1 and a good1 clear colour on the grain4 ,a satisfactory tannage is obtained by treating the hides in oak bark liquors1 which1 in the later stages of the process1 may be strengthened with oak wood1 or myrobalan extract1 or pure gambier1 and completing the process in a tepid bath of sumach1 which clears and lightens the colour4 ,the drum is more suitable for the tannage of dressing hides than it is for sole leather4 ,a quick method of drum tanning would be to treat the hides first in a #e per cent4 solution of neradol1 the artificial tannin1 and then complete the process with oakwood1 chestnut1 or quebracho extracts1 or even in mixtures of these extracts4 ,in this way1 fairly good leather could be made in about two days4 ,neradol prevents the drawn grain and dark coloration that would result from the use of vegetable extracts alone4 ,in the case of light skins1 such as calf1 goat1 and sheep1 the method of vegetable tannage again differs from those just described1 although there is a fair quantity of calf skins tanned with oak bark1 especially those used in the shoe trade4 ,the tendency1 however1 is to complete the process rapidly by using extracts1 such as oakwood1 quebracho1 or mimosa4 ,a very good tannage for the production of a mellow and plump leather is that of pure gambier1 the colour produced forming a good ground for brown shades4 ,where light1 fancy colours are required on the finished leather1 this tannage must be completed by placing the skins in a tepid bath of sumach4 ,a large proportion of the vegetable-tanned sheep and goat skins is produced by sumach alone1 which was adjudged by the ,commission appointed a few years ago by the ,royal ,society of ,arts to investigate the cause of decay in bookbinding leather to be the best tanning material and the one least affected by exterior conditions1 such as gas1 sunlight1 air and dust4 ,many sheep skins are split into two sections by machine before tanning1 the top portion1 known as the grain1 being tanned in sumach1 and described as skivers4 ,the under section1 the side near the carcase1 is known in the trade as a lining1 and is usually made into the so-called chamois leather by means of the oxidation of fish oils4 ,other noteworthy vegetable tannages are those used in the production of ,russia leather1 and a large proportion of ,east ,india leather4 ,real ,russia leather1 of which the raw material consists of small native hides and calf skins1 has a characteristic and pleasant odour1 which is derived from the birch and willow barks used in the tanning process4 ,birch bark contains an essential oil1 which is permanently fixed on the fibres of the leather during the process of tanning4 ,this leather is only produced in ,russia1 and chiefly in one large tannery1 although imitations are made in ,great ,britain1 ,america1 and ,germany4 ,these are produced by the use of ordinary tanning materials1 and the scent is applied1 either during or after the dyeing process by the addition of birch tar oil1 which is made by the distillation of birch bark4 ,in some respects1 for example1 in brilliance of finish1 smoothness of grain1 and freedom from defects1 the imitation is better than the real1 but the latter has the great advantage that its perfume is of superior fragrance and permanent1 whereas the imitation leather only retains the odour for about a year4 ,it is somewhat remarkable1 in view of the good demand that exists for the leather1 especially in ,england and ,germany1 that no firm outside ,russia has thought it worth while to produce the genuine article4 ,the tannage would be particularly serviceable for bookbinding leather1 as the oil of the birch has both insecticidal and antiseptic properties4 ,the principal vegetable tannage used for ,indian leather1 namely1 the bark of the acacia arabica1 known to the natives as babul1 or babool1 has quite a contrary effect1 for it contains a large quantity of red colouring matter1 which is incorporated with the leather in the tanning process1 and although it shows very little in the rough-tanned leather1 it is apt to darken if the finished leather is exposed to strong light for a long period4 ,this oxidation is accompanied by a gradual weakening of the fibres of the leather1 which is1 therefore1 quite unsuitable for bookbinding4 ,fortunately1 ,indian tanners are making rapid progress in using other tanning materials1 a good number of which are found in ,india4 ,although the bark of the acacia arabica is not altogether satisfactory1 the pods of the same tree1 which are commercially known as bablah and contain nearly twice as much tannin as the bark1 produce a very light-coloured1 almost white1 leather1 and it is asserted that this material is a valuable substitute for sumach4 ,,mineral ,,tannages ,by far the most important of the mineral tannages is the chrome process1 the merits and demerits of which have not only been freely discussed in the trade1 but also in the lay press4 ,fanciful theories of the poisonous character of this kind of leather have been published from time to time in the daily press4 ,such absurd statements as that prussic acid and mercury are used in the manufacture of chrome leather hardly need refuting1 as1 even if they could convert skins into leather1 the cost would prohibit their use4 ,the only poisonous acid used in one of the many chrome processes is chromic acid1 but this is converted into the oxide of chromium in a second bath and is1 therefore1 made quite innocuous4 ,the chrome tannage is effected either by the one-bath method or the two-bath4 ,in the former case1 the tanning agent1 either a basic chromium sulphate or chloride1 is present in the one liquor used2 in the latter method1 the hides or skins are impregnated with a solution of chromic acid1 which is reduced to chromic oxide in a second bath consisting of sulphurous acid and a small quantity of free sulphur4 ,the properties of leather produced by the two-bath process render it especially suitable for vulcanising on rubber2 hence its large use for non-skidding bands for motor tyres4 ,there are several recipes for making one-bath liquors4 ,a favourite mixture consists of chrome alum and sodium carbonate 7common soda74 ,another method consists of reducing a solution of chromic acid with glucose or grape-sugar4 ,this liquor has a greater plumping effect on the leather than the chrome alum liquor has4 ,a third process of making a one-bath liquor combines the use of bichromate of potash and chrome alum1 which1 when dissolved1 is converted into a basic chrome salt by means of a reducing agent4 ,the one-bath liquor can be easily and safely applied to hides and skins1 and is used in much the same manner as a vegetable tan liquor1 beginning with a weak solution and gradually increasing the strength until the process is completed4 ,the two-bath method needs great care1 as a slight difference in the proportions of the ingredients used may alter the character of the leather produced4 ,the formula now largely used is practically the same as that of the original patentee1 ,augustus ,schultz1 an ,american chemist4 ,the first bath1 the chromic acid solution1 is made by treating bichromate of potash or soda with hydrochloric1 sulphuric1 or formic acids4 ,bichromate of potash and hydrochloric acid 7commonly known as muriatic acid1 or spirits of salts7 are commonly used1 and in the proportion of #e per cent4 and #b-a_/b per cent4 of the weight of the drained pelts 7#e lb4 of bichromate and #b-a_/b lb4 of acid for #ajj lb4 of pelts74 ,the chemical reaction is represented by the following equation-- ,k#b;,cr#b,o#g #b;,h,cl #b,k,cl #b;,cr,o#c ,h#b,o ,bichromate of potash ,hydrochloric ,acid ,potassium chloride chromic acid water4 ,this process is most conveniently carried out in the paddle-vat 7,fig4 #be71 which1 in this case1 should be fitted with a wooden cover to exclude light1 since the colour of the chromic acid liquor is affected by strong light4 ,some chrome tanners prefer to use the drum tumbler 7,fig4 #ac71 but the pounding of the skins by this method is apt to make the grain loose4 ,whichever method be adopted1 the hides or skins should be horsed up to drain for several hours before transferring them to the second bath4 ,it is important that they be placed grain to grain and smoothed out1 as creases and air bubbles between the skins become fixed in the second liquor1 and depreciate the value of the finished leather4 ,to avoid this danger1 many tanners pass the hides or skins through a striking-out machine under light pressure4 ,another detail of importance is to cover the chromed skins with canvas or matting to keep them from the light4 ,although the skins are preserved by chromic acid1 they are not made into leather1 for in this condition they would dry quite horny4 ,hence1 it is undesirable that the hides should be dried at this stage and sold as leather1 although such a proceeding has been attempted4 ,further1 chromic acid is an irritant poison which may cause an eruption on the hands and arms of workers handling the hides in this solution1 unless they are protected by rubber gloves1 or by coating the hands with a mixture of vaseline and lanoline4 ,the second bath consists of chemicals which reduce the chromic acid to the oxide1 which is quite inert1 so that there is no danger whatever of contracting a poisoned foot as the result of wearing chrome leather4 ,the chemicals largely used for the second bath are hyposulphite of soda and hydrochloric acid4 ,sodium sulphite may also be used without the addition of acid4 ,the skins change from an orange colour to a pale1 bluish-grey tint1 but the process is not completed until a cross section shows that the colour has changed right through the skin4 ,a suitable proportion is #aj per cent4 hypo and #b-a_/b per cent4 acid 7#bh ,twaddell7 calculated on the weight of the drained pelts4 ,calf1 goat1 and sheep skins are usually treated in the drum1 but hides1 especially if a certain degree of firmness is required1 are preferably run in the paddle-vat4 ,the reaction of the chemicals in the second bath are somewhat complicated1 but the principal point is the reduction of the chromic acid 7,cr,o#c7 to chromic oxide 7,cr#b,o#c74 ,the sulphurous acid produced acts as the reducing agent1 but is not freely liberated until towards the end of the process1 the skins first changing into a dirty brown colour which gradually gives place to a beautiful pale-bluish tint4 ,the last stages of the process are also marked by the formation of free sulphur1 which aids materially in softening the leather1 and giving the two-bath chrome tanned leather its characteristic rubbery texture4 ,the vats in which this process is carried out should always be fitted with lids to confine the strong sulphurous fumes4 ,by adding an excess of hypo1 the skins can be bleached until they are nearly white4 ,this has no harmful effect on the leather1 but makes it softer1 though somewhat looser on the grain4 ,when completely tanned1 the skins are horsed up again1 left to drain for at least twenty-four hours1 and are then ready for dressing and finishing4 ,the recipes for the one-bath process are numerous1 but it is becoming a common practice for tanners to buy the liquors or extracts already prepared in chemical works1 which are1 naturally1 better fitted up for the production of a more uniform material than it would be possible to make in most tanneries4 ,,combination ,,tannages ,combination tannages have steadily grown in favour during the last few years1 and will probably have an important bearing on future methods of tanning4 ,among those found practicable are3 7#a7 ,vegetable and chrome2 7#b7 vegetable and alum2 7#c7 alum and chrome2 7#d7 synthetic and natural tannins2 7#e7 synthetic and chrome2 7#f7 alum and synthetic2 7#g7 formaldehyde and chrome2 7#h7 chrome and iron4 ,,chapter ,,vii ,,the ,,dressing1 ,,dyeing1 ,,and ,,finishing ,,of ,,leather ,the dressing and finishing of leathers of all kinds seems to be of growing importance every year1 despite the fact that the durability of leather is often impaired by the chemicals and heavy machinery used in order to get a clear and bright colour or a highly-glazed finish4 ,one exception to this rule1 however1 is japanned and enamelled leathers made by the new collodion-amyl acetate process1 which not only produces the so-called patent finish1 but also adds to the strength of the leather4 ,dressing and finishing may be conveniently classified in four sections-- #a4 ,finishing of boot sole leather4 #b4 ,dyeing and finishing of machine belting1 strap1 harness1 and other heavy greasy leathers4 #c4 ,dyeing and finishing of boot1 portmanteau1 case1 bookbinding1 hat1 and upholstery leathers1 and of the numerous fancy leathers4 #d4 ,dressing1 dyeing1 and finishing of glove and chamois leathers4 ,there are also a few special kinds of leather which do not come within the scope of this list4 ,the limited size of this book makes it impossible to outline the finishing of all kinds of leather1 and only a few of the important varieties can be referred to in the following pages4 ,,sole ,,leather ,formerly1 the finishing of sole leather was a fairly easy matter1 as the slow process of tanning with oak bark which was in general use gave the latter a nice fawn colour4 ,the modern tendency1 however1 is to demand even lighter-coloured leather than that produced by an oak bark tannage1 and1 as most of the mixed tannages impart a darker colour1 the practice of bleaching has been universally adopted4 ,this process is to be greatly deprecated1 since it reduces the strength of the leather4 ,further1 it has the serious drawback of removing matters which would add to the waterproof quality of the leather1 and yet the boot manufacturers demand light-coloured sole leather4 ,as in many other articles of modern manufacture1 quality is sacrificed for appearance4 ,the colour of sole leather is of no importance whatever to the wearer of the boot1 and the public should make a strong protest against bleached sole leather1 and also against leather weighted with adulterants1 if they wish to get boots of good wearing quality4 ,it is difficult to know where the finishing of some of the modern sole leather begins4 ,formerly1 the line of demarcation between tanning and finishing was distinct1 for the finishing processes were begun as soon as the hides were sufficiently tanned4 ,this is by no means the case to-day1 as1 in many cases1 the finishing may be said to begin with a supplementary but unnecessary tannage in very strong tanning extracts1 with the object of making the leather firm and plump1 and1 incidentally1 imparting additional weight4 ,this practice would be discontinued if sole leather were sold by superficial measurement4 ,on the other hand1 those who favour the continuance of the present system of selling by weight assert that the adoption of the measurement system would indubitably result in the production of a lot of under-tanned leather1 that mechanical means would be devised to stretch the leather and thus give it an artificial area1 and that a fair quantity of the leather produced does not lie flat1 and would1 therefore1 be difficult to measure correctly4 ,a great point in favour of selling by measurement is that there would be no necessity to weight the leather1 and a mere visual examination would suffice to determine the quality1 whereas it is often difficult to state whether leather has been treated with injurious artificial matters or not1 and certainly impossible to determine the extent of this fraud1 without a careful and somewhat elaborate analysis4 ,of course1 there are some rough practical tests for ascertaining the quality of sole leather1 especially in regard to the extent of its resistance to water4 ,a weighed quantity of the leather is soaked in water for twenty-four hours1 taken out1 squeezed1 dried1 and reweighed4 ,if the loss of weight does not exceed #e per cent41 the leather is a good sample and well tanned2 on the other hand1 it does not follow that a loss1 say1 of #dj per cent41 would indicate adulteration with injurious materials1 as the leather may have been tanned with an excess of strong extracts which have not properly combined with the fibres1 with the result that the excess is easily removed in contact with water4 ,however1 methods of fixing tanning extracts on the fibres of the leather have been devised 7see p4 #aag74 ,a careful note should be made of the time required to soak the leather through2 if water is absorbed rapidly1 the leather is1 naturally1 unfit for soles4 ,after the tanner has taken great pains to produce the paleness of tint required1 the shoemaker buffs away the grain1 thereby reducing the resistance of the leather to wear1 and then generally covers it with a black1 tan1 or white dressing4 ,in its turn1 this finish is likewise spoiled the first time the leather is worn4 ,there could be nothing more futile than the elaborate finishing of sole leather to make it pale in colour1 as it means that fully #hj per cent4 of the leather produced has to be bleached in some way or other2 and the manner in which this process is effected has a direct influence on reducing the wearing quality of the leather4 ,if1 for example1 the colour of the leather is brightened with myrobalans1 or sumach1 or with extracts of these materials1 the wearing quality is not affected2 unfortunately1 this method is not largely used1 as it does not increase the weight of the leather and would tend to make it soft4 ,a large proportion of sole leather is treated with strong sulphited extracts1 which both bleach and increase the weight of the leather4 ,in some cases1 the leather is placed in vats containing hot tanning extracts to increase the bleaching effect and add to the weight4 ,the gain of weight by this surplus tannage may be1 and often is1 from #h per cent4 to #aj per cent41 and1 whereas the tanner a century ago used to get only slightly above #ej per cent4 of leather on the weight of the raw hide1 it is no uncommon thing nowadays to get a yield of nearly #gj per cent4 ,the tanners are hardly to be blamed for this practice1 which really ought to be stopped2 it is almost entirely due to the demand of buyers for leather at a low price per lb41 irrespective of its superficial area compared with a higher-priced and often cheaper article4 ,it is only fair to state that those boot manufacturers who have taken careful costings of their leather have not suffered great loss in this way1 but most repairers buy common leather in order to be able to do their work at fixed prices usual in this trade4 ,a large proportion of this leather is under-tanned or weighted1 and1 in either case1 absorbs water like a sponge4 ,this kind of leather is quite unfit for soles1 and ought to be condemned1 as it not only absorbs moisture but also retains it for a long time1 so that it is frequently a cause of colds and other complaints arising from chills4 ,if the repairer does not cost his leather as accurately as the wholesale boot manufacturer1 the latter often neglects to take into account the quality of the leather1 so long as cheap soles can be cut from it4 ,the continual demand for leather which will yield low-priced soles has brought about another practice which is much worse than the use of hot extracts4 ,in this case1 the hides are not tanned thoroughly1 but1 instead of completing the process with tanning extracts1 the leather is treated with cheap chemicals1 such as epsom salts 7magnesium sulphate71 glucose1 and barium salts4 ,these add considerable weight and save the cost of expensive tanning materials2 further1 it is claimed that they give increased firmness and substance to the thinner parts of the leather1 which otherwise could not be used for soles4 ,it is conceivable1 therefore1 that leather of this kind could be cut to greater advantage than that properly tanned1 but1 since this artificial filling is washed out on the first contact with water and the leather rapidly deteriorates through attracting and retaining moisture1 the fraud of the system is at once apparent4 ,although the use of leather artificially weighted with hygroscopic chemicals is extremely detrimental to health1 it was only during last year that laws were passed forbidding the adulteration of leather1 and even these are inadequate4 ,strange to relate1 the two countries where these legal measures have been taken1 ,australia and ,south ,africa1 enjoy for the most part a hot and dry climate1 while it is in wet weather that adulterated leather is most harmful4 ,however1 to ,australia belongs the honour of initiating legal measures against frauds in leather manufacture1 and their praiseworthy action must soon be copied by other civilised countries4 ,on the other hand1 it would be inadvisable to prohibit the addition of every other material except those with tanning properties4 ,there are undoubtedly a few substances which1 used in combination with the tanning materials1 add to the strength and value of the leather1 and it is the opinion of some tanners that great developments will take place in this direction4 ,certain oils1 sulphonated in order to render them easily miscible with water1 and known commercially as soluble oils1 exercise a beneficial effect when mixed with the tan liquors1 for they lubricate the fibres of the leather1 assist penetration of and fix the tannin4 ,the time required for the process is1 therefore1 much reduced1 as strong liquors may be used without harmful effect4 ,the oil also serves as a lubricant for the fibres1 obviates the harshness and brittleness usually associated with rapidly-tanned leather1 and fixed to the extent of about #c per cent41 must increase its durability4 ,best of all1 from the tanner's point of view1 there is a moderate increase of weight4 ,there are two or three special tanning oils on the market4 ,a vegetable gummy product has lately been introduced to the trade which has been found to give remarkable results when used in conjunction with tanning materials4 ,this gummy matter is extracted from vegetable seeds and is placed on the market under the name of ,tragasol4 ,its composition is somewhat similar to that of tannins1 the ,tragasol ,co4's analysis showing it to contain #dc4ea per cent1 of carbon1 #f4bc per cent4 of hydrogen1 #dh4ch per cent4 of oxygen1 #j4ci per cent4 of nitrogen1 and #a4di per cent4 of ash4 ,it is very largely used for strengthening and sizing textile fabrics1 and seems destined to play an important part in the leather trade1 for it has tanning properties1 increases the strength of the leather1 and considerably hastens the process4 ,its most important advantage is that it permits successful tannage in the drum1 thus effecting a great saving of time and labour4 ,hitherto1 rapid tannages have not been very successful1 as they generally made the leather harsh and brittle1 and lessened its durability4 ,leather tanned by previous rapid methods was also less waterproof than that tanned in pits by slow methods4 ,all these defects are avoided by using ,tragasol1 which1 when combined with tanning extracts1 forms a curdy precipitate1 described by the makers of ,tragasol as cutiloid 7contraction of cutis and colloid1 cutis meaning skin1 and the ,tragasol being1 chemically1 a colloid74 ,the cutiloid tannage increases the water-resistant properties of leather1 and prevents the oxidation and consequent darkening of the colour of the tanning material used with it4 ,tests have been made which show that cutiloid-tanned leather will withstand a fall of water #ab in4 high for six weeks before complete penetration takes place2 ordinary tannages do not often resist water for more than a few hours4 ,for the tannage of sole leather in the drum by the cutiloid process1 about #abj per cent4 of ,tragasol and #dj per cent4 of chestnut or oakwood extract are required2 this quantity is divided into four equal portions1 which are added to the drum successively at intervals of one hour4 ,the hides should then be nearly tanned through1 and the process is completed with strong extract 7chestnut and quebracho1 or myrobalans1 according to the kind of leather required74 ,after drumming the hides for ten hours1 they should remain at rest for two hours1 then drummed another hour1 and so on1 alternately1 until the completion of the process1 which may require from twenty-four to thirty-six hours1 according to the substance of the hides4 ,by this process1 the yield of leather may exceed #fj per cent4 of the weight of the raw pelts4 ,this percentage of yield may be raised to #gj per cent4 or more in the case of sole leather by steeping the hides in hot extract4 ,the action of acids in swelling gelatine is sometimes abused1 particularly on the ,continent and in ,america4 ,as pointed out before1 tan liquors must be mildly acid in character before the process can proceed1 and1 if the organic acids of the tanning materials are insufficient1 the addition of a small quantity of formic1 or lactic1 or acetic acid is necessary2 but1 in many of the ,american acid tannages1 an excessive quantity of mineral acid is used1 with the object of swelling the hides4 ,when in this condition1 they rapidly absorb an abnormal quantity of tannin1 and the finished leather is unnaturally thick4 ,to make matters worse1 the tannage is sometimes not completed1 but1 instead1 the hides are treated 7doped7 with hygroscopic chemicals1 which not only increase the weight of the leather but also endanger the health of those who have to wear it4 ,most of the ,american tanneries make no secret of their use of these unnecessary chemicals1 but assert that they are obliged to use them in order to meet competition1 and because a large number of bootmakers insist on buying sole leather at a low price per lb4 ,the ,leather and ,paper ,department of the ,u4,s4,a4 ,bureau of ,industry analysed several ,american leathers in #aiac and found that a large majority were artificially weighted with glucose and ,epsom salts 7magnesium sulphate74 ,barium compounds are also used for the same purpose1 but the ,american tannages are apparently free of this adulterant4 ,the results were published in a pamphlet by the ,united ,states ,government1 together with a list of the firms whose leathers were tested4 ,while the ,european tanners do not weight their leather so freely as the ,americans with these chemicals1 the practice of swelling the hides unduly is not unknown1 with the difference that1 especially on the ,continent1 the swollen fibres are fixed by treating the hides with a weak solution of formaldehyde1 which also acts as a preliminary tanning agent4 ,the tannage can then be rapidly completed with fairly strong extracts1 as the formaldehyde prevents the contraction of the grain which would ensue if untreated raw pelts were placed in strong tan liquor4 ,the acid-formaldehyde process is risky1 and cannot be recommended4 ,the use of the artificial tannin1 neradol1 has replaced it in many ,continental sole-leather tanneries4 ,a preliminary tannage with neradol forms a good mordant for the use of the strong extracts4 ,illustration3 ,,fig4 #bf ,,pinning ,,sole ,,butts ,whatever the method used to improve or depreciate the natural tannage1 the surplus material left on the surface is raised or brushed off1 and1 after the leather has been left to drain for a few hours1 it is sent to the finishing department1 which is usually the drying shed4 ,there1 it is left piled up for a day or two1 until it is in the right condition for oiling4 ,the leather must be oiled1 otherwise the grain would be harsh and brittle when dry1 and would darken in colour1 especially at the edges4 ,cod oil is generally used1 and sometimes a little mineral oil is added to it to prevent possible impurities in the fish oil rising to the surface of the leather or causing damage in other ways4 ,a cod oil purified by distillation would1 however1 be quite safe to use1 and there seems to be no reason why tanners should use crude oils so frequently as they do1 now that a large number of oils specially prepared for the leather trade are available4 ,linseed oil is also used in admixture with cod oil1 its oxidising properties hastening the process of drying4 ,the leather is liberally oiled with a brush or swab on the grain side and immediately hung up in the drying shed1 where it is left until it reaches what is technically known as a sammed condition 7i4e41 just damp enough to exude no water when the leather is doubled over74 ,it is then struck out 7pinned7 on the grain side1 either with a hand tool 7,fig4 #bf7 or by machine4 ,in the former case1 the leather is placed on a long wooden beam and the pinner works from the left side1 keeping two of the three edges of his knife flat on the leather while making heavy forward strokes4 ,as the scum is worked out1 the operator mops it up with a wet cloth4 ,machinery has replaced hand labour in this operation in all modern tanneries4 ,the pressure of the tool removes scud and dirt1 varying in quantity according to the amount of bloom contained in the particular tanning materials used4 ,the leather is then laid in pile for a few hours1 when it is in a fit condition for the first rolling1 which is known in the trade as rolling on4 ,this operation is generally done by machine 7,fig4 #bg7 nowadays1 but the old method of using a hand roller heavily weighted with an iron box 7,fig4 #bh7 is still practised in a few yards4 ,after rolling1 the leather is hung up again until nearly dry1 when it is taken down and sized with a weak colouring matter1 made up of annatto or tumeric1 with chalk or whitening dissolved in white vinegar 7acetic acid7 and diluted4 ,it is then rolled again 7rolling off7 and polished with a piece of flannel4 ,finally1 it is hung up to air off1 and is then ready for the warehouse4 ,illustration3 ,,fig4 #bg ,,rolling ,,machine ,in many yards the finishing consists merely in striking out the leather1 rolling it when properly tempered1 hanging up until nearly dry1 and re-rolling4 ,an ,american machine for giving the final polish to sole leather has lately been introduced4 ,instead of the rolling machine1 some ,french tanners use the hammering machine1 which gives good results1 but is necessarily slow and frightfully noisy in action4 ,the steel hammer moves up and down with remarkable rapidity1 but only a small area is covered by each blow4 ,illustration3 ,,fig4 #bh ,,old ,,method ,,of ,,rolling ,,sole ,,leather ,the artificial drying of sole leather1 or of any other kind1 is a matter that needs careful attention1 for it is obvious that great delay would occur1 and a large amount of business would be lost1 if tanners relied solely on the climatic conditions of the ,british ,isles2 in fact1 the weather is so rarely fit for drying leather that every up-to-date tannery contains some artificial aids1 the need for which has been more pressing since a large proportion of leather contains a surplus of tanning matter which is liable to oxidise in contact with strong light and air1 thereby darkening the leather and making it brittle4 ,among the satisfactory drying plants are those of ,howard-,smith ,co41 and the ,sutcliffe ,ventilating and ,drying ,co41 ,ltd4 ,both work on the theory of fanning a continuous current of hot air through the drying-room1 so that the moisture evaporating from the leather is constantly drawn off while the apparatus is at work4 ,illustration3 ,,fig4 #bi ,,fan 7,howard-,smith system7 ,the ,howard-,smith plant consists of a series of steel tubes into which hot water or steam is pumped4 ,these pipes are enclosed in a chamber in which the air naturally acquires great heat4 ,a fan 7,fig4 #bi7 is fixed in one side of this chamber 7,fig4 #cj7 and1 when in motion1 drives the hot air through a wide tube which leads to the drying chamber4 ,illustration3 ,,fig4 #cj ,,fan ,,fixed ,,in ,,chamber 7,howard-,smith system7 ,figure #ca shows the ,sutcliffe ,fan and ,heater installed in a tannery4 ,at least two hygrometers should be hung up in a drying-room to determine the amount of moisture in the air4 ,,chrome ,,sole ,,leather ,the manufacture of chrome sole leather suitable for ordinary walking boots is of comparatively recent origin1 although natural chrome hides were dressed more than twenty years ago for tennis boot soles and other athletic shoes4 ,there can be no doubt of the superior wearing and waterproof qualities of well-dressed chrome sole1 but its high price1 compared with that of vegetable-tanned sole leather1 is against its general use4 ,either the one bath or two bath tannage 7described on p4 #ajh7 may be used1 but1 on the whole1 the one bath method is preferred for the following reasons3 7#a7 ,its application is easier2 7#b7 it produces a firmer and less elastic leather2 and 7#c7 there is practically no danger of weakening the hide fibres4 ,on the other hand1 the two-bath process produces a plumper leather which can1 naturally1 carry more dressing and command a correspondingly better price4 ,in skilled hands1 it is also under better control than the one-bath process1 while it is absolutely necessary for the popular pale bluish-grey tint of chrome leather tennis soles4 ,illustration3 ,,fig4 #ca ,,sutcliffe ,,system ,,of ,,drying ,the natural chrome sole requires very little dressing4 ,the chromed hides 7usually rounded into butts or bends1 shoulders and bellies7 are allowed to remain on a horse two or three days after the completion of the tannage1 so that the oxide of chromium may combine more firmly with the fibres4 ,they are then placed in the drum tumbler again and washed in cold water for several hours4 ,a constant stream is conveyed to the drum through a rubber pipe fixed to the tap1 and escapes through small holes in the drum4 ,the acid salts are not thoroughly removed by this washing and must1 therefore1 be neutralised with an alkali4 ,borax is the best for the purpose1 owing to its mild action on leather and antiseptic properties4 ,from #a to #b per cent4 borax on the weight of the leather is generally sufficient1 while1 if soda be used for economical reasons1 only half the quantity is required4 ,the drum is revolved for about an hour2 the liquor is then run off1 and the leather receives a further washing in cold water for half an hour1 when it is in a condition to receive the dressing1 which is chiefly composed of materials which help to fill and lubricate the interstices of the fibres so that the substance is maintained and the natural strength of the fibres preserved4 ,gelatine1 pure glue1 ,tragasol1 paraffin wax1 carnauba wax1 spermaceti1 ,marseilles soap1 are among the various ingredients used2 while the delicacy of the tint may be improved with china clay or ,french chalk4 ,recipes vary considerably1 each manufacturer claiming to have secret methods4 ,solutions are made of the ingredients1 or1 where one or more of the materials are insoluble1 they are atomised in a mixing pan before use4 ,to induce thorough penetration1 the dressing liquid may be applied to the leather at a fairly high temperature1 as chrome leather is unaffected by heat which would destroy the fibres of ordinary vegetable-tanned leather4 ,even so1 it is inadvisable to use a higher temperature than #agj ,f4 ,the leather is thoroughly impregnated with the dressing in about an hour's time1 and is then piled on a wooden horse for several hours1 or overnight1 to drain and permit thorough incorporation of the dressing with the leather4 ,when well-drained1 the grain of the hides is smoothed by pressure with a special tool 7,fig4 #cb7 or by machine1 the operation being known technically as striking out4 ,the machine 7,fig4 #cd7 gives quite satisfactory results and has replaced hand labour in all modern works4 ,the hides are then strained 7i4e41 extended and nailed to wooden frames71 or they are simply hung up to dry4 ,in the latter case1 there is a small shrinkage of the size of the hide1 but the substance is maintained4 ,with good straining1 a satisfactory increase of surface measurement can be obtained4 ,illustration3 ,,fig4 #cb ,,sleeker ,when the leather is completely dried1 it may be sold at once1 but if1 as is generally the case1 a special nap finish is required on the flesh side1 the hides are placed in damped deal sawdust until they are in the right condition of flexibility for the next process1 known as fluffing4 ,this is done on a rapidly revolving wheel 7,fig4 #cc7 covered with emery powder varying in the size of grain according to the effect desired on the finished leather4 ,the abrasion of the leather on the flesh 7i4e41 the under side7 raises a soft nap4 ,carborundum1 a special abrasive made in ,america1 by the fusion of sand1 coke1 and salt at a very high temperature1 has to some extent supplanted the use of emery4 ,as a final finish1 the flesh side may be rubbed over with chalk or china clay to give it a clear saleable appearance4 ,illustration3 ,,fig4 #cc ,,fluffing ,,machine ,the chrome sole leather used for ordinary boots is quite a different product1 and it is only in the last two or three years that it has been used to any extent4 ,the ,dri-ped is the best known make of this leather4 ,the tannage is effected by the one or two-bath methods already described4 ,the processes preparatory to chroming are very important1 as it is essential to get the maximum yield of pelt4 ,the hides are1 therefore1 often treated with sulphide of sodium1 which loosens the hair in twenty-four hours or less4 ,they are then placed in fairly strong limes for two or three days to swell the fibres and saponify the grease4 ,after being washed in cold water1 the hides are treated with a weak solution of lactic1 boracic1 or butyric acid1 or butyrate of ammonia1 to remove all trace of lime1 when they are ready to be chrome-tanned4 ,after chroming them1 neutralisation of the acid chrome salts is effected with borax1 and the leather is ready for dressing4 ,the principal objects of this process are to make the leather firm and waterproof1 and to remedy its tendency to slip easily on wet pavements4 ,the last-named is the greatest difficulty1 and there are only about two or three firms who have really surmounted it4 ,each manufacturer keeps his recipe secret1 but the ingredients that go to make the various dressings are drawn from the following3 ,stearines1 mineral oil1 ,tragasol1 resin1 carnauba wax1 beeswax1 paraffin wax1 glue4 ,resin1 or asphalt1 or both1 may be used to prevent the leather slipping in contact with a wet pavement4 ,one patent describes a method of dressing chrome sole leather with a mixture of asphalt1 resin1 and paraffin wax4 ,illustration3 ,,fig4 #cd ,,striking-,,out ,,and ,,scouring ,,machine ,the waterproofing ingredients are preferably applied to the leather in the tumbler at a high temperature1 say1 #afj-agj ,f4 ,after running the drum for about three-quarters of an hour1 the leather is impregnated with the mixture1 and is then horsed up for at least twenty-four hours to allow complete incorporation of the fatty ingredients with the fibres of the leather4 ,a suitable waterproof dressing and filling increases the strength of the leather4 ,the finishing of the leather is simple4 ,the butts or bends are smoothed and stretched out by machine 7,fig4 #cd71 oiled on the grain1 nailed or extended with special metal grips on square wooden frames1 and dried4 ,in some cases1 they are hung up until nearly dry1 rolled by machine instead of being put on boards and aired off in a drying stove4 ,a patented method of making waterproof chrome sole leather to prevent it slipping and losing its shape in wear consists in first treating the leather in a solution of glue1 gelatine1 agar-agar1 or other colloidal substance1 with the addition of formaldehyde1 and then submitting it to strong pressure under the influence of a high temperature1 in order to fix the colloidal matters4 ,the pressure is made between heated plates4 ,the leather is afterwards impregnated with a mixture of wool-grease1 pitch1 asphalt1 resin1 wax1 gutta-percha1 etc4 ,a recipe given in the specification consists of wool grease 7#fj parts71 asphalt 7#aj parts71 soft pitch 7#be parts7 and gutta-percha 7#e parts74 ,the mass is fused and kept at #ij ,c4 ,the hides are placed flat in this mixture1 which they quickly absorb4 ,if the ,british ,government should ever introduce a ,bill to stop the adulteration of leather1 it may be found somewhat difficult to deal with chrome sole1 which must have some filling material to make its use practicable4 ,no exception can be taken to the dressing of leather with materials that make it waterproof and increase its strength2 in fact1 much more will be done in this direction than has ever been attempted in the past1 as waterproof sole leather is a necessity in ,great ,britain4 ,any measure to check the adulteration of leather must1 therefore1 clearly define the chemicals which are known to be harmful in leather and which may not be used4 ,this has not been overlooked by the ,australian ,government1 which has forbidden the use of barium salts in leather1 and likewise the importation of leather boots or any goods made of leather containing this chemical4 ,such goods sent to ,australia are liable to confiscation1 and it is reported that a few consignments of boots have already been condemned4 ,leather1 either exported or imported1 must not contain more than #c per cent4 of glucose unless the percentage is marked on each consignment1 in which case1 it is presumed1 a tanner may use as much of the adulterant as he likes1 although the fact that he has to disclose this practice acts as a deterrent in most cases4 ,unfortunately1 the ,australian ,act leaves an important loophole1 since the use of ,epsom salts1 which can be made to increase the weight of leather more than any other chemical1 is not prohibited4 ,in any case1 none of these hygroscopic materials is of any use to chrome sole1 for they would attract moisture which it is desirable to resist4 ,,vache ,,sole ,,leather ,as its name implies1 vache sole leather is a ,continental product1 being made chiefly in ,france1 ,belgium1 and ,germany4 ,the raw material consists of light and medium cow hides4 ,the details of working are somewhat similar to those used in tanning ,english sole leather1 the main difference being that the hides are suspended in the lime liquors instead of throwing them in flat4 ,the system of tannage is not so varied as the ,english1 since the materials used generally consist of oak and pine barks1 myrobalans1 quebracho and oak extracts2 and the finishing materials are of quite another character4 ,the ,continental tanners generally use the ,raumur thermometer1 while the ,beaum hydrometer is used to determine the density of the tan liquors in place of the ,english barkometer 7,fig4 #bd74 ,one degree ,beaum is equal to #f4i barkometer4 ,vache leather is more pliable than ,english sole leather1 but the addition of valonia extract towards the end of the tanning process would greatly increase its firmness4 ,the finish is applied to the flesh side of the leather1 and a typical recipe consists of a size such as ,irish moss or ,tragasol 7#a part71 flour 7#bj parts71 china clay 7#bj parts71 and pure gambier 7#b parts7 in #bjj parts of water4 ,the size is dissolved and cooled1 and the other ingredients are then added4 ,,machine ,,belting1 ,,harness1 ,,and ,,saddlery ,,leathers ,these leathers are rarely made by one firm2 usually1 strap butts and most kinds of belting leathers are dressed by curriers1 whose trade is quite distinct from that of currying shoe leather4 ,the tanning and currying of harness and saddlery leathers is another special branch4 ,besides these three important trades1 there is the dressing of hydraulic1 mechanical1 and other industrial leathers1 which likewise form special sections of the heavy leather industry4 ,belting leather is an important item in the trade1 and1 as a good proportion is made from the finest hides1 this class of leather is among the most expensive made4 ,at present1 there is much controversy in the trade as to whether the vegetable-tanned or the chrome-tanned article is the more economical in use4 ,briefly1 chrome belting is superior in works where there is much steam or mineral acids1 as it is not affected by these conditions to the same extent as bark-tanned belting4 ,its tensile strength is also greater1 but against these advantages must be set its higher cost and tendency to stretch unduly in comparison with the vegetable-tanned product4 ,it can be safely said1 however1 that the use of chrome belting is on the increase1 although its production is not nearly on such a big scale as that of the old type of belting4 ,the tannage of belting leather is similar to that of sole leather1 except that there is no necessity to continue the process1 after the tannin has struck through1 with the object of increasing its firmness and weight4 ,attention must also be paid to the class of tanning materials used1 especially for belting of the best quality1 as it must have great tensile strength and stand a severe strain in the dynamometric test4 ,tannins that rapidly oxidise in contact with light and air have1 therefore1 to be avoided4 ,the oak bark tannage1 with a little chestnut and oakwood extracts to finish the process1 is a good method of imparting to the hide the right degree of firmness and flexibility4 ,as in the case of sole leather1 belting may be artificially weighted during the tannage1 although it is usually done in the currying process1 if at all4 ,there can be no doubt that a quantity of adulterated belting leather is made1 and will continue to be made while the practice of selling by weight is in vogue4 ,as a rule1 sophisticated belting leather has a much weaker tensile strength than the pure product and is of relatively poor value1 since the reduction of price is usually a matter of only a few pence4 ,if users of belting bought on the principle of value instead of price1 they would never buy adulterated leather4 ,illustration3 ,,fig4 #ce ,,leather-,,stuffing ,,drum ,in tanning hides for belting1 the shoulders and bellies are cut off and usually dressed for sole or harness leather1 leaving the butt1 the prime part of the hide1 #d-a_/b ft4 in length 7,fig4 #bc74 ,the tanned butt is first shaved to level the substance1 then washed in a solution of borax1 and sumached in the drum4 ,after smoothing the leather in the striking-out machine1 it is partially dried 7sammed7 and then rubbed on both sides with a dubbin of cod oil and tallow4 ,in this condition the butts are left piled up for a few days1 so that the dubbin penetrates the leather1 which is then extended with the sleeker 7,fig4 #cb7 to make it smooth and to remove surplus grease1 which is sold to soap-makers under the currier's name of moisings4 ,the leather is finally dried1 rolled 7optional71 stretched by machine1 and cut up in the width of belting required4 ,instead of hand-stuffing the leather with cod oil and tallow1 which is still the best method1 a large quantity of butts are now drum-stuffed1 the object being to make use of stearines1 which are harder and heavier greases than tallow4 ,the type of drum shown in ,figure #ce1 in which the grease is incorporated with the leather by means of live steam1 gives satisfactory results1 although hot air apparatus is now replacing the steam injector4 ,a patent has lately been granted to an ,american inventor for the production of a strong and cheap belting4 ,flesh splits of hides are simply stuck together with a collodion or nitrocellulose solution4 ,any number of layers may be used1 according to the substance required1 the only essential quality being that the leather should be free from grease4 ,the adhesive property of nitrocellulose solutions is probably stronger than that of any other material1 but1 unfortunately1 the tough film they form on drying does not grip a greasy surface4 ,before the solution used to join the pieces of leather together is dry1 the leather is rolled under heavy pressure1 and1 when thoroughly dried1 can be cut up for belting4 ,the dressing of harness leather is similar to the manual process of making belting1 with the exception that the butts or bends 7half butts7 are stained either black or a pale straw colour1 the latter being known to the trade as the ,london colour4 ,annatto is often used to get this colour4 ,the bright1 greasy finish on harness leather is obtained by rubbing buck tallow over the grain and polishing with a glass sleeker or a piece of flannel4 ,the operation is sometimes done by machine1 in which the working cylinder is covered with pieces of cotton rag4 ,saddlery leathers are dressed on similar lines1 but the finish is not so greasy as harness4 ,pig skins make the best and toughest leather for this purpose4 ,they are dressed in a similar manner to harness hides1 but special attention has to be given to pig skins to get rid of the large quantity of natural grease they contain4 ,,boot ,,upper ,,leathers ,whereas the number of different kinds of boot upper leathers in use less than three decades ago was limited to five or six 7waxed calf1 calf kid1 ,french kid1 mock kid1 levant1 coloured calf7 it is now almost legion4 ,although the variety is almost bewildering1 however1 the popular demand is confined to about half-a-dozen sorts1 which include real and imitation box calf1 box hide1 glac or glazed kid1 patent leather1 willow calf1 dull-finished chrome leather1 and waxed kip butts and waxed splits for workmen's boots4 ,box leathers and glazed kid are the most popular of all4 ,generally speaking1 glazed kid is more suitable for wear in the summer and autumn2 while box leather1 being thicker and stronger1 is preferable for the winter4 ,imitation willow calf 7i4e41 calf skin tanned in vegetable and chrome liquors1 either separately or combined7 is very suitable for easy-wearing boots1 but is not so durable and resistant to water as the pure chrome-tanned article4 ,the tannage of box and willow leathers may be effected by the one or two-bath process already described 7p4 #ajh74 ,before the tannage1 it is advisable to pickle the hides or skins in a solution of alum and salt1 with the object of preventing contraction of the tissues of the hide1 and providing a mordant for the more rapid absorption and fixation of the chrome salts4 ,the tannage completed1 the acid salts in the leathers are neutralised with borax1 and after the leather has been washed in warm water it is ready for dyeing4 ,the dyeing of box calf is generally done in the drum tumbler1 but there are several other methods4 ,one system used on the ,continent is to dip the skins1 a pair at a time and placed flesh to flesh1 in a very strong dye liquor4 ,this method is slow1 and not in accordance with modern ideas2 used for producing browns and fancy shades1 it is very difficult to avoid irregularity of colour where large parcels are manipulated4 ,another method is vat dyeing1 the process being carried out in a wooden vat 7,fig4 #be7 and the dye liquor circulated by means of a paddle4 ,the one advantage of this system is that the leather can be easily examined during the process4 ,a useful method of dyeing is carried out by brushing the colouring materials on the grain side of the leather4 ,this process is economical1 and it has the further advantage that the finished leather can be used for unlined boots and other purposes where an undyed flesh is necessary4 ,the original box leather was dyed a dark-blue shade in the drum before it was shaved1 and1 as the dye does not penetrate very far into chrome leather1 unless a strong mordant of tannin be previously used1 the subsequent shaving left the flesh side of the leather a very pale-bluish tint4 ,the process of dyeing is least troublesome and most effective when done in the drum tumbler4 ,the leather is run in warm water until the temperature reaches #adj-aej ,f 7#fj-ff ,c47 and the dyeing materials are added gradually in a box at the side of the drum whence it passes through the axle or journal into the tumbler4 ,although chrome leather is not materially affected by boiling water in contradistinction to vegetable-tanned leather1 which cannot be treated with water above #fj ,c4 without injury1 it is inadvisable to dye it in boiling solutions1 the above-mentioned temperature being the most satisfactory4 ,there are two methods of dyeing blacks in the leather trade3 7#a7 the logwood-ammonia1 and 7#b7 the aniline black4 ,the former is the cheaper of the two and quite satisfactory1 although many dyers seem to prefer the aniline process4 ,the latter certainly gives a deeper black1 but it is not at all necessary to make the flesh side of box calf black1 and many buyers prefer the back blue1 although1 of course1 the grain side of the leather must be finished a jet black4 ,the crude logwood is generally subjected to a process of fermentation or ageing4 ,the new wood has to be placed on stone or cemented flooring in a warm room and frequently turned over until fermentation has ceased1 which usually takes about a week4 ,it is then cut into small chips by machinery and packed in bags4 ,this is the form in which it always used to enter the tannery1 but it is now generally prepared in paste or crystal extract by makers of tanning and dye-wood extracts1 a business which grows in importance every year4 ,the colouring matter of logwood is haematoxylin1 which is converted into haematin by oxidation2 hence1 the extract is often referred to as haematin crystals4 ,the paste may be used where it is desirable to increase the substance of the leather1 but most dyers prefer the crystals1 which are easily dissolved in hot water4 ,one lb4 of crystals1 to which is added just enough ammonia to change the brown colour to violet blue1 suffices for each #ajj lb4 of leather dyed4 ,the colouring matter is absorbed by the time the drum has been running half an hour1 leaving clear water behind4 ,the next process is known technically as fat-liquoring1 which1 as its name implies1 consists in lubricating the fibres of the leather with fatty or oily matters4 ,this is a very important process1 for1 when suitable ingredients are used1 the pliability1 strength1 and waterproof quality of the leather are greatly increased4 ,the making of special fat-liquors for different kinds of leather has become quite an important business1 and most makes can be depended upon for the specified purposes4 ,it is a debatable point as to whether fat-liquoring should precede or follow dyeing4 ,generally speaking1 it is better to adopt the latter course1 as the fatty ingredients help to fix the colouring matter on the fibres of the leather4 ,the dye is also less liable to fade when fat liquoring follows the colouring4 ,the number of materials that may be used for the process of fat-liquoring is almost legion1 but the principal are soaps1 oils1 egg-yolk1 tallow1 flour1 ,tragasol1 ,irish moss1 china clay1 and starch4 ,unless the special preparations made by leather trade chemical firms be used1 much care has to be exercised in selecting the most suitable ingredients for each class of leather4 ,for example1 the mixture that would give good results on vegetable-tanned leather might be quite unsuitable for chrome leather4 ,then1 again1 the selection of material is based on the style of finish required1 a dull finish necessitating heavy fats and greases which would be quite unsuitable for bright leathers1 and particularly for those of the chrome-tannage4 ,among the hundreds of recipes that have been published from time to time1 tallow has only found a place in one or two mixtures1 yet it is one of the finest materials for strengthening and lubricating the fibres of leather4 ,if its splendid properties were fully known1 it would be very largely used for fat-liquoring purposes4 ,of course1 it is well known to the currying trade1 having for several centuries formed the basis1 together with cod oil1 of the dubbin used in stuffing waxed leather and belting butts4 ,the following is a useful recipe for a fat-liquor for box calf3 #b lb4 ,marseilles soap and #c lb4 neatsfoot oil for every #ajj lb4 of leather4 ,the soap is cut into small pieces and dissolved in hot water1 and the oil is added slowly and thoroughly mixed by stirring vigorously4 ,where possible1 emulsification should be done in a machine1 in order to atomise the ingredients4 ,the finer they can be brought into a state of division1 the better they will be absorbed by the leather4 ,other suitable fat-liquors for box leathers are the following3 7#a7 ,turkey red oil1 #b per cent4 of weight of leather and neutral soap #a per cent43 7#b7 neatsfoot oil1 #b lb42 tallow1 #a lb42 and ,tragasol1 #a lb43 7#c7 cod oil1 #b lbs42 ,marseilles soap1 #a lb43 7#d7 neatsfoot oil1 #b lbs42 egg-yolk1 #a_/b lb41 or six fresh yolks4 ,the process is completed in #bj-cj minutes4 ,in the case of fancy colours or browns1 the leather should generally be well-drained and warmed up again in the drum in hot water 7#agj ,f47 before fat-liquoring1 but the precaution is unnecessary for black leathers4 ,after the fat-liquoring process1 the leather is removed from the drum1 and piled up on the horse to drain1 and left for several hours or overnight1 to allow it to assimilate the fatty ingredients4 ,it is then submitted to an operation known as sleeking or striking out1 with the object of removing surplus water and so facilitating drying1 and making the grain side smooth4 ,machinery is now almost universally employed1 especially for chrome leather4 ,a good type of striking out machine is shown in ,figure #cd4 ,if done by hand1 the skins are placed on a sloping glass or slate table1 with the flesh side uppermost1 which is then stretched out by strong pressure with a tool known as a sleeker1 the strokes being made downward in the direction of the hair growth4 ,the flesh side done1 the whole skin is turned over and the grain side is similarly treated4 ,sometimes only the flesh side is struck out1 especially if the grain is soft and tender4 ,the sleeker consists of an iron1 steel1 or copper blade1 about #f in4 square1 fitted in a wood handle 7,fig4 #cb74 ,the skins are hung up in the drying-room immediately they are extended and smoothed by sleeking1 and are then either allowed to dry completely1 or1 as is generally the case with best leather1 they are hung up until a great deal of the moisture is evaporated and the skins are left in a slightly moist1 or1 as it is generally termed1 sammed condition4 ,the skins are then taken down1 damped in dry parts1 folded over1 laid in piles to equalise the moisture1 and finally smoothed out and stretched again by hand or machine4 ,this second operation after the dyeing is known as setting4 ,chrome-tanned skins are usually stretched and nailed on square boards after setting1 as1 owing to their elasticity1 they are liable to shrink considerably in drying4 ,the superficial area can be increased by fully extending the skins4 ,this operation is technically described as straining4 ,it may be stated here that vegetable-tanned leathers are not generally strained on boards1 as such leather is better in quality and substance when hung up and dried4 ,leather of combined tannage 7i4e41 tanned with vegetable and chrome products7 is1 however1 frequently strained1 as the astringent property of chrome would otherwise cause contraction of the fibres4 ,when dried on the boards the leather is somewhat stiff1 and has1 therefore1 to be softened before any finishing ingredients are applied4 ,chrome leather is softened by placing it for a few days in damp sawdust1 which1 for brown or fancy coloured leather1 must be of deal or white pine1 and1 therefore1 free from objectionable colouring matter2 but1 for black leather1 the sawdust of any wood is suitable4 ,the skins must be systematically piled one above the other1 and a little damped sawdust scattered over each skin4 ,when properly seasoned1 the skins are brushed free of the sawdust and staked1 either by hand or machine1 usually by the latter means4 ,the staking knife may be fixed in a wood crutch 7arm stake71 or fixed upright in a vertical wooden stand 7knee stake74 ,in the former case1 the skins to be staked must be secured in a horizontal wooden groove fixed to two uprights1 the workman then pressing heavily in a downward direction with the staking knife1 of which the crutch is held under the armpit4 ,in using the upright stake1 the leather is moved to and fro over the edge of the fixed knife4 ,both of these manual operations are arduous and somewhat dangerous1 and should be displaced by machinery wherever possible 7,fig4 #cf74 ,illustration3 ,,fig4 #cf ,,staking ,,and ,,glazing ,,machine ,the thoroughly softened leather is then dried1 mordanted with a solution of logwood1 or haematin crystals1 blacked with levant ink1 a specially prepared black dye1 or with a suitable aniline dye1 and dried again4 ,it is finally seasoned with a glutinous or albuminous mixture 7blood albumen1 milk1 and a little aniline black dye make a good mixture71 dried1 glazed1 seasoned a second time1 and reglazed4 ,a light coating of mineral oil turns the finish into a jet black1 and the leather is ready for the warehouse4 ,there are several types of glazing machines1 but the grasshopper 7so called owing to its action7 is the most popular for box calf4 ,this machine is the same as shown in ,figure #cf1 except that the working tool is replaced with a smooth glass or agate roller4 ,the term box applied to this leather was invented by a prominent ,american tanner1 and had he registered the name and patented his process he would have reaped a very rich harvest1 for the leather is used in enormous quantities throughout the world4 ,as it was1 the ,american firm tried to obtain an injunction against ,english firms manufacturing the leather1 but had to withdraw their claim1 as they were not the inventors of chrome leather1 which was made in ,scotland before it was introduced to the ,states4 ,moreover1 the word box1 as applied to leather1 was not registered in the ,united ,kingdom4 ,willow calf is exactly the same kind of leather as box calf1 except that it is dyed brown instead of black4 ,the seasoning mixture naturally differs and may consist of a mixture of egg albumen1 milk1 and a little of the same1 or similar1 dye solution as that used in the dyeing process4 ,in order to get clear colouring1 the dyes should be well dissolved and strained through fine muslin4 ,,chamois ,,leather ,this kind of leather is well known to the general public under the name of wash-leather1 but it is1 perhaps1 not so widely known that there is practically no real chamois leather available1 since the species of animal bearing this name is almost extinct4 ,nowadays1 chamois1 or shamoy is made from the flesh split of sheep skin1 and the method whereby the leather is produced is described as the oil tannage4 ,the chamois leather dresser may also do the preliminary work of fellmongering1 but more often he receives the pelts1 or fells1 from the fellmonger4 ,although the pelts have been in a lime liquor known as the fellmonger's gathering limes1 the process of liming has to be continued and carefully regulated4 ,too much liming makes the pelts loose1 owing to the development of bacteria4 ,this effect would cause the finished leather to be soft and spongy4 ,on the other hand1 under-liming fails to remove sufficient of the cement substance which binds the fibres of the pelts2 consequently1 the leather produced from these pelts is thin and somewhat gristly4 ,after being limed1 the skins are cobbed 7i4e41 the bits of wool or hair left on by the fellmonger are removed7 and the pelts are then fleshed by machinery4 ,the next operation1 splitting1 is very important and requires skilful attention to get good results4 ,the ,reeder machine is largely in use1 but the band-knife machine is also suitable4 ,the top half of the sheep skin 7i4e41 the grain side7 is utilised for the manufacture of skivers1 while the under portion1 or flesh side1 technically called lining1 serves as the raw material for chamois leather4 ,the best linings are generally sorted out for making into parchment1 which1 of course1 commands a much higher price than chamois4 ,linings for chamois are then submitted to the operation of either re-splitting or frizing1 the object being to remove the loose tissue lying between the grain and flesh4 ,the pelts are re-split in the case of cheap chamois1 but frized if intended for choice finish4 ,frizing is an operation peculiar to the making of chamois and glove leather4 ,it is done with a very sharp knife1 similar to the fleshing knife1 and on a more upright beam than that used by tanners4 ,the work requires great skill1 frizers being among the best paid workers in the trade4 ,frizing done1 the linings are freed from lime by washing them in the drum tumbler1 or paddle-vat1 through which cold water is allowed to flow continuously for two or three hours4 ,when lamb skins1 which are too thin to split1 are made into chamois leather1 the grain is removed by frizing4 ,a quick and effective method of deliming is to treat the skins in a weak solution of lactic acid4 ,some dressers use a drench of pea-flour or bran4 ,the mild acids produced by the fermentation of these materials not only neutralise the lime but also reduce the gristly nature of the skins to a soft1 supple condition4 ,the bran infusion is slightly warmed to hasten the process of fermentation1 but the temperature must not exceed #ajj ,f4 7#cb ,c474 ,the linings are then rinsed in cold water and sent to the stocking machines1 in which they are kneaded until they become quite soft4 ,either the faller-stocks or the mechanical pushers 7,fig4 #ad7 may be used1 the latter being the more modern machine4 ,the operation may require from four to ten hours1 the completion being determined by the condition of the skins4 ,samming follows stocking1 and for this purpose the linings are hung up in the drying shed until thoroughly dripped1 but not dried4 ,in this slightly damp condition they are then prepared for the next process of oiling1 which is the most important part of chamois-dressing1 as it converts the perishable raw linings into leather4 ,in the ,united ,kingdom1 cod oil 7generally ,newfoundland7 is used exclusively1 and gives best results4 ,whale and shark liver1 or menhaden oils are often used abroad4 ,the linings are placed in a tub or vat1 a few at a time1 and oil is poured over each layer until a sufficient number has been treated to fill the stocking machine4 ,the stocks are run for half-an-hour1 or until the oil has penetrated the linings1 when they are put back into the vat1 where they remain for about an hour4 ,they are then re-stocked1 taken into the shed to samm1 re-oiled in the vat1 and stocked again4 ,these processes are repeated until the skins are thoroughly impregnated with the oil1 when they are dried in a warm stove4 ,the skins are not yet converted into leather1 which only occurs in oil-dressing1 after the oxidation of the oil4 ,this is effected by spontaneous heat1 the dry oiled skins being heaped in boxes and covered4 ,strict attention has to be paid to avoid over-heating the skins1 which are turned over and changed at intervals4 ,when the leather ceases to heat1 the process is completed4 ,it is then dipped into hot water and mechanically pressed1 to remove surplus or uncombined oil1 which is collected and sold under the name of sod oil4 ,the leather is afterwards drummed in warm water and finely cleansed in an alkaline solution1 potash1 soda1 or borax1 chiefly the first named1 being used for this purpose4 ,they are then rinsed in water1 dried1 damped1 and softened by staking4 ,at this stage1 the best skins are sorted out for the glove makers4 ,the others are finished for wash-leather by re-staking1 paring with the moon-knife1 and smoothing both sides of the skin with a scurfer1 or fine pumice-stone4 ,in the warehouse1 they are damped1 stretched out1 piled up1 and kept fully extended by placing heavy weights near the edges of each pile of skins4 ,,gloving ,,leather ,progress in the art of making leather for gloves has been rapid during the last few years2 but further important developments are expected1 particularly in the process of tanning4 ,practically the only method that has been used for many decades for converting kid1 lamb1 and sheep skins into gloving leather is that known technically as tawing1 which consists of treating skins with alum1 salt1 egg-yolk1 flour1 and a vegetable oil4 ,these substances change skins into extremely supple and stretchy leather1 but when this is made into gloves it is far from ideal in wear1 because it fails to keep the hands warm in cold1 wet weather1 it is easily soiled and cannot be cleaned without great expense1 and it is not very strong in texture4 ,combination tannages have lately been produced1 however1 which remove the defects of alumed leather4 ,by means of a light chrome tannage after tawing1 the leather is strengthened and made more resistant to water1 and can be cleaned with a damp rag or sponge4 ,by tanning skins with the formaldehyde process1 or with ,neradol1 the artificial tannin1 for making into sude leather1 the finished article is not only washable but also resists the action of alkalies and soap4 ,the adaptation of combined tannages in the manufacture of gloving leathers has only lately been developed1 and further improvements will doubtless be effected before long4 ,lamb1 kid1 goat1 and sheep skins constitute the raw material for gloving leathers1 although deer and antelope skins are also used to a small extent4 ,real kid skins are the best wearing dress gloves1 but the great majority of so-called kid gloves are made of lamb skins4 ,the raw kid and lamb skins are chiefly of ,european1 ,arabian1 and ,indian origin4 ,sheep skins from the ,cape provide the raw material for a large number of men's gloves1 and leather of very good quality can be produced from the best grades4 ,most of the skins are preserved by drying1 or by salting and drying1 although some kid skins are wet-salted and packed in barrels for export4 ,it would save leather-dressers a great deal of trouble if they could always get wet-salted skins2 but the object of drying them is to reduce the weight and lower the cost of freight4 ,soaking is done by methods already described 7p4 #fe74 ,loose flesh and pieces of fat are cut off in order to facilitate the action of the depilitant1 of which the best for glove leather is undoubtedly a paste of lime and red arsenic4 ,seven or eight parts of lime to one of arsenic is a satisfactory proportion1 the quantities to be mixed depending on the number of skins to be treated1 as a fresh mixture should be made for each lot1 or pack as the tanner terms it4 ,the lime should be well broken up1 or1 better still1 pure powdered lime should be used and the red arsenic well mixed with it2 a little water is then added to slake the lime gradually1 and the mixture is stirred to promote chemical reaction4 ,the compound is further diluted with water until it has the right consistency and the colour has changed4 ,the reaction generates great heat1 and the paint should1 therefore1 not be used at once4 ,the flesh side is mopped with the paint and the skins are folded flesh to flesh4 ,after a few hours1 or as soon as the hair or wool is loosened1 the skins are dehaired or dewoolled4 ,the hair or wool is not allowed to come into contact with the depilitant1 otherwise it would be damaged4 ,in large yards1 the white hair is separated from the coloured1 as it is worth nearly twice as much4 ,wool is sorted into different qualities1 of which the number may vary from four to eight1 or even nine1 according to the class of skins treated4 ,the pelts are then thoroughly washed and placed in lime liquors1 where they remain for one or two weeks1 being hauled and set in the usual manner4 ,fleshing and piecing or trimming are the next operations1 and then follows the very important process of puering1 which1 in the case of glove leather1 must be thoroughly done so as to reduce the pelts to a very soft and flaccid condition4 ,success in the making of glove leather depends largely on the puering process4 ,in most of the ,english tanneries a decoction of dog manure is used1 at a temperature not exceeding #ij ,f41 but on the ,continent the artificial puer1 oropon1 is preferred4 ,it is much safer to use and more uniform in its action than excrement1 which develops bacteria rapidly in contact with gelatinous pelts1 and could ultimately destroy them entirely4 ,after puering them1 the pelts are well washed and submitted to the process of drenching1 which consists in putting the skins into a warm infusion of bran or pea-flour and leaving them covered until the following morning4 ,the slightly acid fermentation causes the pelts to rise to the top of the vat4 ,they are pushed into the liquor again with a pole and stirred round4 ,this is repeated three or four times to prevent damage to the grain4 ,the process is often done in the paddle-vat 7,fig4 #be71 in which the bran liquor is circulated for several hours before the pelts are allowed to remain quiescent4 ,drenching thoroughly purges the pelts of the last traces of lime1 and puts them in suitable condition for being made into leather4 ,the pelts are then rinsed in tepid water and scudded on the grain with a slate or vulcanite tool1 shaped somewhat like a dehairing knife4 ,the scud removed consists of dirt1 dissolved lime salts1 short hairs1 and pigment4 ,machines are rapidly replacing manual labour for this operation4 ,the alum tannage1 known technically as tawing1 is largely used for kid and lamb gloves4 ,the tawing mixture is composed of alum1 salt1 egg-yolk1 and wheaten flour4 ,the proportions used vary considerably in different tanneries1 but the following is a typical recipe3 #d lb4 alum1 #b lb4 salt1 #a lb4 salted egg-yolk1 or the yolks of twenty fresh eggs1 and #e lb4 flour for #ajj lb4 of pelts4 ,the flour is made into a paste1 the egg yolk is diluted in warm water and mixed with the flour1 the salt and alum are dissolved and added1 and the mixture thoroughly stirred4 ,a suitable quantity of water 7about #b gals4 per #ajj lb4 pelts7 is then placed in the drum tumbler1 the tawing mixture is added1 and the drum revolved for a few minutes before putting the pelts in4 ,the process is completed in two or three hours in the case of thin skins4 ,it is a good plan1 however1 to leave them at rest in the drum for a day1 after which they are piled up overnight to allow further combination of the tawing materials with the fibres of the pelts4 ,the leather is then dried out completely1 damped in clean sawdust1 or by sprinkling with water1 levelled by shaving if necessary1 staked over an upright knife fixed in a wooden stand or by machine1 and dried in a hot stove4 ,in this condition1 or in the crust1 as dressers term it1 the leather is allowed to remain several weeks to age1 a most essential process for the production of soft1 and supple glove leather4 ,dressing and dyeing are begun as soon as the leather is satisfactorily aged4 ,the skins are uniformly soaked in warm water1 dyed1 and re-dressed with egg yolk 7re-egged71 to which a small quantity of olive oil1 or a sulphonated oil1 is added4 ,some dressers prefer to give the second tawing mixture before dyeing1 but the advantage of dressing the leather after dyeing is that the colour is securely fixed4 ,in re-egging1 many dressers use a similar mixture to the first dressing4 ,the dyeing process is of great importance1 since the colour must be fast4 ,the leather is dyed either in the drum or on a convex table4 ,in the former case1 the leather is naturally coloured both sides1 while1 in the latter1 it is stained with a brush on the grain side only4 ,staining is the more difficult method4 ,kid glove leather may be dyed with aniline colours1 or1 as more generally practised1 with natural dye-woods as a base and aniline dye for top-colouring4 ,the great advantages of the latter method are economy in dye-stuffs and increased depth of colour4 ,the skins are first prepared for dyeing by brushing with1 or drumming them in1 an alkaline solution4 ,stale urine was largely used for this process1 but ammonical salts are now generally preferred1 if only for sanitary reasons4 ,the skins are then drummed or paddled in1 or brushed with1 dye-wood liquids which have been carefully strained4 ,a large selection is available1 including fustic1 cuba wood1 saffron1 peachwood1 logwood1 sappan wood1 cutch1 ,persian berries1 gambier or terra japonica1 and golden tan bark4 ,light and medium brown can be obtained from these dye-woods without the aid of aniline colours2 but for dark shades1 and to increase the brilliancy of other colours1 a top dye or coal-tar dye is often given4 ,the natural dyes are further developed with strikers1 which mainly consist of metallic salts4 ,iron1 copper1 and zinc sulphates1 nitrate and acetate of iron1 bichromate of potash1 and titanium salts 7titanium lactate1 titanium potassium oxalate1 and tanno-titanium oxalate7 are the most important4 ,the lactate1 sold commercially under the name of corichrome1 is especially suitable1 as1 unlike the mineral acid salts1 especially the sulphates1 it has no destructive effect on the fibres of the leather4 ,dye-woods are now concentrated in the form of a paste1 or dry extract1 the latter being the more reliable4 ,they are also very convenient to use and dissolve1 while mixtures are1 of course1 easily prepared4 ,a good tan shade on ,cape sheep can be obtained by mordanting the leather with a solution of #a lb4 of bichromate of potash for every #ajj lb4 of leather1 drumming it in #h-i lb4 of pure gambier1 and then with a mixture of cuba wood extract1 #a lb42 fustic extract1 #c_/d lb42 ,brazil wood extract1 #a_/b lb42 and logwood extract1 #a_/b oz4 ,after drumming the leather in this dye liquor for about an hour1 the colour is developed with corichrome4 ,if a darker shade be required1 the leather can be treated with a suitable basic dye4 ,after dyeing the leather1 some dressers only fat-liquor it with egg-yolk and a small quantity of olive oil1 while others prefer to re-dress it with a similar mixture to that used for tawing1 namely1 alum1 salt1 egg-yolk1 and flour2 but1 where titanium salts are used1 the latter method is not essential1 because titanium has tanning properties4 ,when dry1 the leather is ready for finishing1 but it is advisable to keep it in store for a few days before packing it in damp sawdust or sprinkling it with water to prepare it for the operation of staking4 ,anything more unlike leather would be difficult to imagine at this stage1 but1 after stretching the skin in the staking machine1 or by drawing it over the upright stake1 the dry1 stiff1 and shrivelled leather is reduced to a very supple condition4 ,the flesh side of the leather is then pared with the moon-knife1 or in the shaving machine1 to equalise the thickness4 ,in some works1 a special tool which pares the leather on a flat table is preferred2 this particular operation is called doling4 ,the flesh side is finished by fluffing it on the emery or carborundum wheel 7,fig4 #cc74 ,finally1 the grain is brushed and polished with the glass sleeker1 or ironed4 ,chamois leather has been largely used for gloves of late years1 but this leather has the defect1 in common with sude leathers1 of getting soiled much more quickly than grain leathers1 such as kid1 lamb1 or ,cape sheep4 ,nevertheless1 sude and chamois gloves are likely to remain fashionable to a more or less extent4 ,the manufacture of chamois leather is described on page #add4 ,sun-bleached skins are the best for dyeing1 especially if delicate shades are wanted4 ,the frontispiece shows a field covered with skins bleaching in the sun4 ,chemically bleached leather is likely to become discoloured after dyeing4 ,defective skins are often dyed with pigments 7dust colours71 and this system is also applied to skins which have to be dyed such delicate shades as cannot be produced by wood or aniline colours4 ,although it gives attractive results to the eye1 and certainly covers up any defects of the grain1 this method of dyeing is not altogether satisfactory1 as the leather remains unpleasantly dusty in wear for quite a long time4 ,the dyeing of chamois with wood-dyes or coal-tar colours is by no means easy1 but this method gives the best results when successful4 ,the grease must first be removed from the leather with a solution of #e lb4 of borax or #c-a_/b lb4 of soda for every #ajj lb4 of leather4 ,if the leather is still greasy on the surface1 a further quantity of soda or borax is given1 after which the leather is well washed in warm water1 sumached1 rinsed to remove the particles of sumach1 and mordanted with titanium salts4 ,the dyeing is then done with anilines or wood-dyes1 or a combination of both1 and this is followed by fat-liquoring with egg-yolk and a sulphonated oil4 ,the finishing operations are staking and fluffing4 ,to get a good1 fast black on chamois and sude leathers is one of the difficult processes in the leather trade1 although it is easier to get a good black on alumed or chromed leather than on vegetable-tanned4 ,alumed leather is washed in a solution of borax or carbonate of ammonia to remove uncombined dressing in order to prepare it for dyeing4 ,chrome-tanned sude leather does not need this preparation4 ,the leather is first mordanted with dye-wood extract1 of which a suitable mixture is logwood and fustic1 or logwood and quercitron1 in the proportion of #d lb4 and #b lb4 to every #ajj lb4 of leather4 ,after drumming the leather in this solution for about an hour1 a weak solution of copperas 7ferrous sulphate7 and bluestone 7copper sulphate7 is added1 and the milling is continued for twenty minutes1 when the leather is well prepared to receive the black dye4 ,instead of the iron and copper salts1 corichrome is often preferred1 as it is quite safe to use1 whereas iron salts have a destructive action on the fibres of the leather1 unless the precaution be taken to mordant the skins with a good quantity of dye-wood extract4 ,following the application of the iron or corichrome striker1 the leather is dyed with suitable aniline black 7leather black1 or corvoline7 and finally fat-liquored to nourish the leather1 and to fix and intensify the black4 ,this recipe also gives good results where the skins are dyed only on the flesh side1 the solutions being applied with a brush4 ,,white ,,washable ,,leather ,among the new kinds of leather for gloves1 none is more remarkable or more useful than the washable sheep or goat skins4 ,the great advantage of this leather is that it can be washed in warm water and soap any number of times without injury1 whereas gloves of ordinary tawed kid and lamb skins have to be dry cleaned and cannot be renovated many times4 ,an additional advantage of washable leather is its warmth4 ,after being dehaired1 puered and drenched1 the skins are drummed in a solution of formaldehyde and soda4 ,in two or three hours1 the skins are tanned1 and are then treated with a solution of sulphate of ammonia4 ,the quantities required are about #c lb4 of formaldehyde 7#dj per cent47 and #h lb4 of sodium carbonate 7#hj per cent471 and #a lb4 of sulphate for #ajj lb4 of pelts1 using sufficient water to cover the skins well in the drum4 ,this tannage produces a white but somewhat thin and empty leather1 and the fat-liquoring must1 therefore1 be filling and softening4 ,an emulsion of white curd soap and olive oil1 or of egg-yolk and neatsfoot oil1 is suitable4 ,crestanol1 a special preparation1 also gives satisfactory results1 since it is adapted for giving nourishment and resiliency to thin1 empty leather4 ,,fancy ,,leathers ,the best known of the fancy leathers is morocco4 ,this variety has been made for ages1 and the name probably originated from the fact that very fine leathers of this kind were manufactured in ,morocco a few centuries ago4 ,history records that a similar leather1 dyed red1 was made in the ninth century before the ,christian era4 ,the best morocco leather is made from ,continental goat skins1 which are mostly obtained from ,central ,europe and ,spain4 ,the ,norwegian goat skins are also said to be of good quality for the morocco finish4 ,an inferior morocco leather1 which is produced in large quantities1 is manufactured from ,east ,india goat skins1 while a cheaper grade still can be produced from certain classes of ,east ,india sheep skins4 ,the real moroccos are tanned in sumach1 but the cheaper sorts are tanned in ,india with babool or turwar bark and re-tanned in sumach in the countries to which they are exported1 chiefly ,great ,britain1 ,germany1 ,france1 and ,america4 ,one of the best methods of sumach-tanning goat and calf skins is that known as the bottle tannage4 ,each skin is doubled over and sewn by machine round the edge1 leaving part of the neck unsewn4 ,the skins are then turned inside out and filled with a strong infusion of sumach1 and floated in a tub containing sumach liquor4 ,after being a few hours in the tub1 the skins are heaped one above the other in a large pile1 where the pressure forces the tannin through the skins4 ,the process can be completed in twenty to twenty-four hours1 after which the skins are cut open1 rinsed1 and finished in the usual manner4 ,this method of tanning is now largely replaced by the use of paddle-vats 7,fig4 #be74 ,the dyeing and finishing are somewhat similar to that of coloured boot upper leather1 except that the leather is slightly oiled on the grain instead of being fat-liquored4 ,there are several different methods of graining morocco leather2 some of the grains are made naturally by pressing the leather1 when folded over1 with a cork-covered board1 while others are first embossed in various ways and then boarded4 ,the well-known crushed morocco is produced by glazing the grained leather under heavy pressure4 ,skivers1 the grain splits of sheep skins 7see p4 #ade7 are extensively used for fancy articles4 ,the majority are finished with a smooth grain for hat-bands1 bookbinding1 and linings4 ,the grain of a sheep skin is1 naturally1 soft1 and not very strong4 ,to stiffen and strengthen the grain1 an artificial layer1 consisting of paste finishes1 is often applied4 ,skins finished in this manner are termed paste grain skivers4 ,these are largely used for bookbinding and cheap purses4 ,sheep grains are sometimes given a finish somewhat similar to that of leather bags4 ,this is produced in a printing machine by means of a copper roller which is run over the damp 7but not too wet7 leather4 ,the skins are then described as long-grain skivers4 ,the grain surface of sheep skins is particularly suitable for embossing1 and wonderful imitations of all kinds of skins can be reproduced on skivers4 ,the fancy leather trade is not confined to these imitations1 however1 as real lizard1 seal1 ichneumon1 alligators1 crocodile1 shark1 porpoise1 snake1 and even frog skins 7,japanese7 are utilised4 ,,index ,acid ,swelling of ,hides1 #aai ,adulterated ,leather1 #aad ,ageing of ,leather1 #aea ,algarobilla1 #dc ,alum ,tannage1 #aej ,annatto1 #acf ,antelope ,leather1 #fc ,anthrax1 #bg1 #fi ,arsenic ,sulphide1 #ga ,bablah1 #de1 #ajg ,babool1 #de1 #ajg ,band-knife ,splitting ,machine1 #ed ,bark ,mill1 #ic ,barkometer1 #ig ,bating1 #hf ,belting ,leather1 #acc ,birch ,bark1 #ajf ---- ,tar ,oil1 #ajg ,bleaching ,leather in ,sun--,frontispiece ,boot ,leather1 #acg ,bottle ,tannage1 #aeg ,borax1 #fd ,box ,leather1 #acg ,buffing ,cylinder1 #ed ,butts1 #ie ,butyrate of ,ammonia1 #he1 #abi ,butyric ,acid1 #he1 #abi ,canaigre1 #de ,cape ,sheep1 #aec ,catechol ,tannins1 #df ,caustic ,soda1 #ff ,celavina1 #dc ,chamois ,leather1 #ah1 #add ,chestnut ,oak1 #cg ---- ,tree1 #cf ,chrome-quebracho ,tan ,liquor1 #cb ,chrome ,sole ,leather1 #abe ---- ,tanning1 #ajh ,cod ,oil1 #ajj1 #abj1 #adf ,collodion1 #acf ,colouring ,pits1 #id ,combination ,tannages1 #aaa ,crestanol1 #aef ,crust ,leather1 #aea ,currying1 #acc1 #ace ,cutch1 #df ,dehairing ,hides1 #ga ---- ,knife1 #hj ---- ,machine1 #hb ,dehydration1 #b ,depilatories1 #gh1 #adi ,disinfection of ,hides1 #b ,divi-divi1 #dc ,doling1 #aec ,dressing ,leathers1 #ajb ---- of ,leather1 #aab ,drenching1 #hi ,dri-ped ,leather1 #abi ,drum-tanned ,leather1 #ajc ,drum ,tumbler1 #ff ,drying of ,leather1 #abc ,dust ,colours1 #aed ,dyeing1 #aab1 #aee ,dye-wood ,extracts1 #aci1 #aeb1 #aee ,ellagic ,acid1 #dg1 #aba ,enzymes1 #gb ,erodin1 #hh ,evolution of ,leather ,manufacture1 #a ,extracts1 #dg ,faller ,stocks1 #ff1 #adf ,fancy ,leathers1 #aef ,fat ,liquors1 #aci ,fellmongering1 #ade ,finishing1 #aab1 #abb1 #abg ,flaying3 ,mechanical method1 #ba ----3 ,pim's method1 #bd ,fleshing ,knife1 #hc ---- ,machine1 #hb ,fluffing1 #abh1 #aec ---- ,machine1 #abi ,foot and ,mouth ,disease1 #f ,formic ,acid1 #bh1 #ff1 #he1 #ie1 #ajj ,freezing ,hides1 #ga ,frizing1 #ade ,fustic1 #aeb ,gallotannic ,acid1 #df ,gambier1 #dj ,glazed ,kid1 #acg ,glazing ,machine1 #adc ,gloving ,leather1 #adg ,goat ,skins1 #ae ,golden ,tan ,bark1 #aeb ,greasy ,hides1 #ab ---- ,sole ,leather1 #ge ,hammering ,leather1 #abc ,handlers1 #id ,harness ,leather1 #acc ,hauling and ,setting ,limes1 #gg ,hemlock1 #dd ,hide ,markets1 #g ,hides and ,skins1 #e ----1 ,curing1 #b1 #bf ----1 ,defects of1 #ai ----1 ,disinfection of1 #b1 #bf ----1 ,horse1 #ag ----1 ,sources of ,supply1 #e ,hyaline ,layer1 #fh ,hypoderma bovis1 #cj ---- lineatum1 #cj ,japanese ,white ,leather1 #c ,lactic ,acid1 #he1 #ie1 #ajj1 #abi1 #adf ,larch ,bark1 #de ,layers1 #id ,leather-working ,machinery1 #eb ,liming1 #ga ,linings1 #ade ,logwood1 #ach ,lysol1 #hd ,machinery1 #eb ,mangrove1 #da ,marseilles ,soap1 #adj ,mimosa1 #db ,mineral ,tannage1 #ajh ,mixed ,tannages1 #aja ,morocco ,leather1 #aef ,motor ,leather ,bands1 #ajh ,myrobalans1 #ch1 #ic ,neradol1 #ej ,oak ,bark1 #cd ,oakwood1 #ce ,oropon1 #hg ,paddle-vat1 #adf ,parchment1 #ade ,pickled ,sheep ,skins1 #aj ,pigments1 #aed ,pig ,skins1 #ah1 #acf ,pinning ,leather1 #aba ---- ,machine1 #aba ,porpoise ,laces1 #ai ,preparation of ,hides for ,tanning1 #fc ,puerine1 #hh ,puering1 #aej ,pyrogallol ,tannins1 #df ,quebracho1 #cb1 #cg ,red ,arsenic1 #ga1 #adi ,reeder ,splitting ,machine1 #ade ,roller ,leather1 #ac ,rolling ,sole ,leather1 #abb ,rounding of ,sole ,leather1 #ie ,saddlery ,leather1 #acc ,samming1 #adf ,scudding1 #hf ,seal ,skins1 #ai ,setting1 #adb ,shaving ,cylinder1 #ec ---- ,knife1 #ee1 #ef ---- ,machine1 #ef1 #fa ,sheep ,skins1 #ab ,skins and ,hides1 #e ,skivers1 #ade1 #aeg ,sleeker1 #abh ,soaking ,hides1 #fe ,sod ,oil1 #adg ,sole ,leather1 #ie ,soluble ,oils1 #aag ,staking ,machine1 #adc ,sterilising ,hides3 ,seymour-,jones's method1 #bh ,straining1 #abh1 #adb ,striking-out1 #abh1 #acj ,stuffing1 #ace ,sude ,leather1 #aed ,sulphide of ,sodium1 #ff1 #gf ,sulphonated ,oils1 #aag ,sumach1 #ch ,suspender ,pits1 #id ,synthetic ,tannin1 #di1 #ie ,tanner's ,beam1 #fh ,tanning ,extracts1 #dg1 #ib ,tanning ,materials1 #cb ---- ,processes1 #ib ,tan-yard1 #id ,tawing1 #aej ,terra japonica1 #dj ,tick ,fever1 #bg ,titanium ,salts1 #aeb ,tragasol1 #aag1 #acj1 #adj ,turkey ,red ,oil1 #ada ,turwar ,bark1 #aef ,vache ,sole ,leather1 #acb ,valonia1 #ce ,warble ,fly1 #bh ,wattle ,bark1 #db ,weighted ,leather1 #aad ,white ,washable ,leather1 #aee ,willow ,bark1 #de1 #ajf ---- ,calf1 #add ,wool ,skin ,dressing1 #ea ,,the ,,end ,printed by ,sir ,isaac ,pitman ,sons1 ,ltd41 ,bath1 ,england