The Puering, Bating & Drenching of Skins
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mutiplied → multiplied
Kothbeize → Kothbeizen
of → on
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pepsine → pepsin
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Frankfort a/M – Frankfort o/M
Zenckeri – zenkeri
Casenin – Caseuin
Kentniss – Kenntnis – Kenntniss
resistant – resistent
c.c. – c.cm.
ureaæ – ureæ
ae – æ
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PUERING, BATING & DRENCHING
Scientia et potentia humana in idem coincidunt, quia ignoratiocausæ destituit effectum. Natura enim non nisi parendo vincitur:et quod in contemplatione instar causæ est, id in operatione instarregulæ est.
Knowledge and human power are synonymous, since theignorance of the cause frustrates the effect; for nature is onlysubdued by submission, and that, which in contemplativephilosophy corresponds with the cause, in practical sciencebecomes the rule.—Bacon, Aphorism III.
THEPUERING, BATING & DRENCHINGOF SKINS
EXAMINER IN LEATHER TANNING, DRESSING OF SKINS, AND LEATHER DYEING
TO THE CITY AND GUILDS OF LONDON INSTITUTE;
MEMBER OF THE INTERNATIONAL ASSOCIATION OF LEATHER
TRADES CHEMISTS, ETC.
SIR JOHN TURNEY
LIGHT LEATHER INDUSTRY
|LIST OF ILLUSTRATIONS|
|I.||DESCRIPTION OF THE PUERING AND BATING PROCESS|
|II.||THE CHEMISTRY OF BATING|
|III.||THE PHYSICS OF BATING|
|IV.||THE BACTERIOLOGY OF THE BATE|
|V.||ACTION OF ENZYMES|
|VI.||ORIGINAL PAPERS ON BATING|
|X.||ORIGINAL PAPERS ON DRENCHING|
|1.||Curve showing removal of lime by washing|
|2.||Cubical “truck” for measuring skin|
|4.||Front elevation of puer wheel|
|5.||End elevation and section of puer wheel|
|6.||Sir John Turney’s scudding machine|
|7.||Curves of ash contents during puering|
|8.||Diagram of volumenometer|
|9.||" connexions of electrometric apparatus|
|11.||Apparatus for measuring degree of falling|
|12.||Curves obtained by measuring apparatus|
|13.||Improved apparatus for measuring degree of falling|
|14.||Various forms of bacteria in puer liquors|
|15.||B. coli commune|
|16.||B. erodiens (Becker)|
|17.||Plate culture from fresh puer|
|18.||" " puer wheel|
|20.||Organisms in pigeon dung, × 1000|
|21.||Pure culture of bacillus (d) from sweated skin|
|22.||" " " (e) " "|
|23.||B. butyricus (Hueppe)|
|24.||Spirillum volutans (Kutscher), stained to show flagellæ|
|25.||" " " unstained preparation|
|26.||Curves showing rate of hydrolysis|
|27.||Organisms in bran drench, × 1000|
|28.||Chains of bran bacteria, × 1000|
|29.||Bran fermentation, advanced stage|
|30.||B. furfuris, α|
|31.||B. furfuris, β|
|32.||Cultures of α in glucose gelatin|
|33.||Gas curve (B. furfuris)|
The present volume is the outcome of a desire topreserve the numerous notes which I have made duringover twenty years’ work at the practical and scientificstudy of bating. It has been my wish to completethe investigation of this important process in leathermanufacture, for, as Lord Allerton has paradoxicallyremarked:1 “Good leather is made before the skinsgo into the tan liquor at all,” but owing to circumstanceshaving drawn me more and more to the commercialside of the business, I have been compelled toabandon this project.
When learning the trade as an apprentice everyfault in the leather was attributed to this part of thework, and the troubles and miseries of the “puer shop”first caused me to take up the study of puering. Iwas determined to know the causes underlying theprocess. Puering is not only a filthy and disgustingoperation, but is prejudicial to health, and in thenature of it is attended by more worry and troublethan all the rest of the processes in leather makingput together.
I think it may now be said, at any rate, that thesolution of the problem of constructing an artificialbate on scientific principles, which will replace thepresent crude methods, is well within sight. Theprincipal obstacles are, on the one hand, the inertiaof English manufacturers; on the other hand, theclass of labour employed in puering is not of thehighest order of intelligence. Innovations in mostthings are resisted, partly because they necessitatechanges in the method of working, and partly becauseof the innate conservatism of human nature. It iscertainly a significant fact that although most of thepioneer work on this subject was done in England, thepractical side has been taken up in Germany, and byfreely spending money on large trials in the works theyhave enabled the manufacture of artificial bates to bedeveloped on a commercial scale.
In 1886, while studying Chemistry under ProfessorFrank Clowes, I began to examine microscopically thevarious liquors of a light leather factory, and moreespecially the bran drenches. At that time I knewnothing of bacteriology, for the simple reason that littlebut pathological work in this line was being done inEngland. Through the kindness of Professor Clowes, Iobtained an introduction to Mr. Adrian Brown (nowprofessor at the University of Birmingham), and in hislaboratory at Burton-on-Trent I saw the first pure cultivationsof Bacterium Aceti which he had isolated, andof which he had completely studied the chemical action.2I had there an opportunity of seeing the methodsand apparatus employed. I also had the benefit ofMr. Brown’s advice in commencing a systematic study ofthe process of drenching. Professor Percy Frankland,then at Dundee, advised me further as to the microscopeand other matters. My warmest thanks are dueto these friends for directing me in the right way.
As a result of my first investigations, on December11, 1889, I read a short paper entitled “Methods ofBacteriological Research—with some account of BranFermentation,” before the Society of Chemical Industry.
The way in which this paper was received led to afurther research into the nature of bran fermentationin conjunction with Mr. W. H. Willcox, B.Sc. (nowSenior Analyst to the Home Office), by which theaction of the bran drench was thoroughly investigated,and the results published in the Journal of the Societyof Chemical Industry, May 31, 1893.
This was followed, on June 30, 1897, by a paper“On a Pure Cultivation of a Bacillus Fermenting BranInfusions,” also in conjunction with Dr. Willcox.
In 1898, in reply to a publication of Director Eitner,of Vienna, I published in the Leather Trades’ Review(November 15), a résumé of the whole subject, entitled“The Rationale of Drenching.”
Already, in the first paper above named (“Methodsof Bacteriological Research”), I had called attention tothe bacteria of the bate prepared from dogs’ dung, andin a paper entitled “Fermentation in the Leather Industry,”3developed this aspect of the subject, and firstpointed out the influence of enzymes in bating. Itherefore decided to study the phenomena occurring inthe bate in the same way as I had studied drenching.
The work was begun in 1895, and, as it was likelyto occupy an indefinite time, the first instalment, entitled“Notes on the Constitution and Mode of Actionof the Dung Bate in Leather Manufacture,” was publishedNovember 30, 1898; while “Further Notes onthe Action of the Dung Bate” was published on November30, 1899.
In these papers I indicated the lines on which aculture of bacteria might be practically applied to thebating of skins, and gave the composition of a liquidwhich, while acting as a nutrient medium for the bacteria,contained at the same time most of the activechemical compounds of dog dung.
Meanwhile, Dr. Popp and Dr. Becker, in Frankforta/M, were investigating independently the bacteria ofdog dung, and conceived the idea of employing themcommercially. My dear friend Franz Kathreiner, ofWorms,4 put me in communication with these gentlemen,and we were thus enabled to work in conjunction.As a result of our combined labours, an artificial bate,called “Erodin,” was put upon the market. This willbe fully treated of in the chapter on Artificial Bates.
I shall give first a short account of bating, and thensum up as briefly as possible the present state of ourknowledge of the process, afterwards giving an accountof the more important of the various patents which havebeen taken out for artificial bates.
Although the book is divided into separate sectionsfor convenience, it is obvious that we cannot separatechemistry from physics, nor bacteriology from chemistry,nor enzyme action from all three.
My own papers are printed as read. The Bibliographydoes not profess to be complete, but includesmost of the works consulted.
No one realizes more than I how incomplete thework is, and how much research still remains to be donein order to complete it.
Thanks to the efforts of the Leather Industries Departmentof the University of Leeds, and the TechnicalCollege of the Leather Sellers’ Company, Bermondsey,the era of Rule of Thumb is passing, and there is littledoubt that the work that is being done in these institutionswill be translated into practical use in thefactories by the coming generation.
I wish to express my special thanks to Mr. Douglas J.Law, and to Dr. H. J. S. Sand for assistance in preparingthe notes for publication, to Dr. J. GordonParker, Director of the Leather Sellers’ TechnicalCollege, London, for the description of the bating ofhides, and to Professor Kràl, of Prague, for some ofthe photographs of bacteria.
JOSEPH T. WOOD.
Nottingham : January 1912.
THE PUERING AND BATING PROCESS.
“Beizen sind Stoffe die mit dem Kalk nicht nur einchemische Verbindung einzugehen im Stande sind, wodurchderselbe löslich und