Class 1V.J
FLAX-STEEPING PROCESSES—CLAUSSEN’S FLAX COTTON.
07
During the last half-century various attempts havebeen made to effect the separation of the fibrous from thewoody portion of the flax stein ;.by chemical and me-chanical means. In several cases the results at firstappeared to be very promising, but in every instance itMas soon found that there were insuperable practical ob-jections, which more than counterbalanced the advan-tages. Among chemical agents, solutions of sulphuricacid, caustic potash, caustic soda, quicklime, and softsoap, were all, in turn, tried and discarded; and amongmechanical processes the ingenious contrivances of Mr.James Lee and Messrs. Hill and Bundy shared the samefate. Mr. Lee, having found a means of separating thefibre of flax without water-retting, and the discoverybeing considered one of very great importance, obtaineda patent for his mechanical process in 1812, with thesingular protection of a special Act of Parliament, byvirtue of which he was exempted from specifying theparticulars of his process during the first seven years ofthe duration of his patent. In 1817, and therefore beforethe publication of his specification, Messrs. Hill and Bundytook out their patent for machinery for breaking andpreparing raw flax and hemp. The rival claims of thesetwo inventors were investigated in 1817 by a committeeof the House of Commons ; but whatever may have beenthe comparative merit of the two processes, in the courseof a very few years both were relinquished and forgotten.Since that time various other ingenious mechanical ar-rangements have been devised, but hitherto they havehad very little success.
Schenck’s process, for which he obtained a patent in1840, is undoubtedly a very important improvement; itconsists merely in steeping the flax stems in warm water,heated artificially to the temperature best suited to fer-mentation. By this simple means, the operation is ren-dered rapid and certain, all uncertainty from fluctuationsin the temperature and weather is avoided, and the wholeprocess is entirely under the command of the manufac-turer. The temperature best suited for this purpose isabout 80°, or from SO 0 to nearly 90° ; above this pointthe process proceeds too rapidly, and the fibre is almostsure to be more or less injured. The time required isfrom about 70 to 90 hours.
From the facts and evidence brought forward by-various independent exhibitors, it appears satisfactorily-proved that the warm-water steeping increases the per-centage of fibre obtained from the flax stem over thatobtained by the old modes of retting by nearly one-fifth;and that, whilst the fineness and spinning qualities of thefibre are increased, the strength is in no way weakenedor diminished, unless the process be permitted to proceedtoo far, an effect which need never happen, from thecomplete control over it which the manufacturer hasthroughout. Although there is no doubt as to the prac-tical value of the use of warm water in flax-retting, yetthe introduction of Schenck’s process is far from removingall the difficulties of the flax manufacture; much stillremains to be effected, and it is by no means improbablethat, ere long, a yet more perfect process may be devised.
It is interesting to observe that the use of’warm waterin the preparation of vegetable fibre is not altogethernew, it having been long employed by the Malays, andby the natives of Rungpoor, in Bengal. The processadopted at Bencooleu is stated by Dr. Campbell to con-sist in steeping the stems of the hemp in warm water,in which it is allowed to remain for two days and nights.
The old German process called “ Molkenrost,” some-times used in preparing the finer sorts of flax, is also, tosome extent, au application of the same principle. Inthis mode of retting, the flax was steeped for four or fivedays in a warm mixture of milk and water, and thus thedesired degree of fermentation in the flax stems wasproduced. This operation must be distinguished fromthe more modern one, in which sour milk was used inorder to give a good colour to linen, a process introducedby the Dutch towards the middle of the last century.Tlie linen was boiled in a weak alkaline lye, and sub-sequently treated with sour buttermilk, for the purposeof aiding in removing the alkali, and dissolving theearthy impurities present in the fibre. Occasionally, also.
; salt of sorrel was used for the same purpose; and in 1775,; Reuss states, that sulphuric and muriatic acids might be! used for the same purpose; but that being too costlv,' they had not as yet come into general use. Of course,
I all processes in which boiling or even hot water is used; are quite different in their mode of action from those inwhich only warm water is employed. When boilingMater is used, it is with a view of dissolving and re-moving the useless matters which encrust the fibrouspart of the plant; whilst, on the other hand, warm wateris used to soften them, and to aid in their putrefaction or: decomposition, through the agency of fermentation. In| 1787, much interest was excited in Ireland by the publica-' tion of a plan for improving the retting of flax by the ac-tion of hot Mater; in this scheme, it was proposed to scaldi tlie flax-stems in boiling water to soften them, and to! remove a portion of the extraneous vegetable matters! which they contain; and it was conceived that after this
• treatment the subsequent retting of the flax would be; more rapid, certain, and manageable; so that time would| be saved, the noisome process of pond-retting be obviated,
' and the result be to yield a stronger and whiter fibre.
The minute aud careful experiments of Hennbstaedt, onthe chemical principles involved in the retting of flax, (made about the beginning of the present century), threw; much light on the whole subject, and to some extent in-
• dicated the influence of temperature ou the success of| the operation.
1 The entire collection shown by the “ Royal Society forj Improving and Promoting the Growth of Flax iu I reland”(1U6, p. 203*) is so highly valuable, and so clearly illus-! trates the great advances which have already been made1 in these matters, and the important service* which thissociety has already rendered to the country, that theJury determined to mark their high appreciation of theSociety ’s labours by the recommending the Council Me-dal. (See p. 09.) Among the individual specimens ofparticular merit may be mentioned the flax exhibited byWhitk, of Antrim, Preston, of Belfast , and Adams, ofBallyderitt, near Coleraine (49, p. 198*) ; to each of thesethree the Jury awarded a Prize Medal.
A very useful and complete series of the principalcommercial varieties of flax, hemp, and similar fibrousmaterials, commonly met with in the English market, iscontributed by Messrs. Hutchinson (40, p. 197*). Thesamples, which arc all good, are as follows:—
Archangel do. Jute.
Hemp.
Petersburg best hemp. Egyptian hemp.
Petersburg half-clean hemp. India brown do.
. Riga Pass do. Manilla do.
American do. Italian do.
For this collection the Jury awarded a Prize Medal.
A numerous series of specimens are contributed by P.Ceaussen (105, p. 202*, 203*), in illustration of his patent| process of making flax cotton. This process (patented; August 1850) consists essentially in boiling the cut aud! crushed stems of the flax, hemp, or other plant, in a dilutej solution of caustic soda, containing about one two-thou-j sandtli part of alkali. The fibrous matter is then re-moved, and plunged into a bath of dilute sulphuric acid,
| containing one five-hundredth part of acid, in which it isj boiled for about an hour. It is next transferred into aj solution containing about ten per cent, of carbonate ofI soda; and lastly, when it has remained in the latter for\ an hour, it is plunged into a weak solution of sulphuricj acid, consisting of one part of acid to two hundred or fivei hundred parts of water; in this it is left for about half: an hour, and the prccess is completed. The effect ofthese several processes is “ to divide and split up ” the fibre; in a most remarkable manner, so as completely to alter: its character. Flax thus treated is converted into a sub-; stance very nearly resembling cotton. It is probable| that llax cotton can be advantageously used in the manu-
u