repeated six or eight times, the cloth is then sufficiently prepared for the sour.*

Cloth, when it can be done, is subjected dry to every boil and every steep. The leys then penetrate the fibrous texture of the thread, are attached to the colouring matter, and dissolve it, and are washed away by pure water, or whitened by pure air; or, according to O'Reilly, reduced to carbon by alkali; the carbon united to the pure air of the atmosphere, or of oxy-muriates, becomes volatile, and escapes in the form of carbònic acid gas. When cloth is immersed wet, the bleaching leys should be stronger. But if cloth is submitted dry to the action of steam in a high temperature, it may be made tender, or dissolved by it.

Some adventurers from England and Scotland, pretending to great skill in the art, and to the knowledge of important secrets in it, came into Ulster, and offered their services, for which they claimed great rewards; whoever practised their schemes upon a larger scale, was greatly injured, the cloth was tender, it mildewed; our manufacture and the new method of bleaching was brought into disrepute by their practice.

Inattention to the strength of the liquid, to the operations of washing, scouring, and scalding after steeping in it, was the cause of these misfortunes. If cloth is exposed on the field, in the stormy months, it will be tossed and often torn; when the days are short and dark, very little benefit is derived from the atmospheric air, it is then subjected to the alternate severe action of leys and mills.

In the summer months the selvages often escape the action of the pure air, and are insufficiently whitened. The black specks formerly described, called firing on flax, and sprit in cloth, adheres to the fibrous texture, through the different manipulations to which flax and cloth are subjected, even till every other part of the thread is perfectly white. In all such cases, the new bleaching liquid, managed with caution, would instantly remove these evils, and preserve the fabric from more severe operations.

* Berthollet, in the second and sixth volumes of Annales de Chemie, and in the Art of Bleaching, by Pajot de Charmes.

Bleaching with oxy-muriates has been tried in paper manufactories. The rags of which the paper is to be made, or else the pulp into which they are reduced, are submitted to their action. This method has been generally relinquished, because paper improved by it in colour, has, in a very few years, impaired the colour of the ink; even printers' ink has been known to fade by the action of the oxy-muriates remaining in it.* These detergents act upon the iron of the cylinder, and occasion iron-moulds. Washing with profusion of pure water in the engine, would remove the remainder of the bleaching liquid, but this would be attended with more trouble and expence than the old method. If paper manufacturers will imitate the method of bleaching described, they will be successful.

Let them attach a small wash-mill, on the plan of the old tuckmills, to their machinery; washing with the cylinder is only rinsing. When the rags are sorted, let them be steeped in kelp or barilha ley, for twelve hours; wrung or pressed and washed, again wrung and wetted with ley, then laid two inches thick upon frames in a steam apparatus, and submitted to the vapour of the ley in which they were first steeped, at the temperature of 250°. This process relaxes and opens the fibrous texture of the threads, and the water in the mill entering them carries off the dirt and colouring matter. If the most beautiful whiteness is required, immerse them in oxy-muriate ley, wash and immerse in acidulous water, wash and beat them into pulp. If the rags are so small that they may be in danger of being lost in the mill, they may be confined in coarse nets. Refuse of tow from flax-mills or hackles, may be prepared for fine paper by a similar process.

Oxy-muriates must be used in discharging the colour from coloured rags, and ink from written paper; even printed paper has . been bleached by the alternate use of the alkaline ley and the blanching liquid; for this purpose, I recommend an engine resembling the engines in use, but with a cylinder of wood. The axis may be of wood, or of glass run upon lead, and secured with leather collars. The case provided with a steam-tight cover. The

Murray's System of Chemistry, vol. 2. p. 565.

rags when beaten into pulp with the steel roller, are to be run into the wooden engine, into which the oxy-muriatic vapour is to be forced from a small apparatus for the purpose. The motion may be given to the wooden cylinder by hand, which will sufficiently agitate the water and the pulp, so as to expose different surfaces to the action of the vapour. The pulp may then be allowed to subside, the water run off and acidulous water run in, agitated and washed' as before. The pulp will then be freed from every thing injurious to the paper. If an apparatus for preparing the oxygenated muriatic acid is inconvenient, the bleaching salt and oxy-muriate of pot-ash can be procured from the vitriol manufacturers at a lower rate than private individuals can prepare them for their own use.

In bleaching cloth, rags, or pulp, with oxy-muriate of pot-ash, the stuffs must be made to pass through acidulous water, that the sulphuric acid may expel the oxy-muriate from its combinations. The alum used in the size for writing paper, will in some measure have this effect. The small quantity of alumine, or of a selenitic compound precipitated, will not have a bad effect on the paper. When oxygenated muriatic acid combined only with pure water is used, washing well, and exposure to the air and light may be sufficient.

This method points out the means of preparing expeditiously and economically, the coarsest tow, the brownest and the dirtiest rags and cloth, being made into the best and whitest pulp for paper.

NOTE. For additional remarks on bleaching, and the process by which it is conducted at Manchester, see Domestic Encyclopedia. ED

198

EXPERIMENT OF ROTTING HEMP,

AGREEABLY TO MR. BRAALLE'S METHOD.

IN the first number of the ARCHIVES, mention was made of a public experiment by M. de Liancourt, of rotting hemp, agreeably to the process of Mr. Braalle: the following account of the experiment is given by himself in a French JournalAnnales de l'Agriculture Française, tome xxii. p. 289.

The government, in diffusing through the departments, instructions to rot hemp in two hours, by Mr. Braalle of Amiens, and in all seasons, invited proprietors to repeat those experiments, the success of which he had ascertained, by repeated trials during four months, as one of the commissioners named by the govern

⚫ment.

M. de Liancourt thought it his duty to attend to this benevolent call the success of the method of Mr. Braalle, was of great importance to the country in which he lived, (Liancourt, department of Oise) where hemp is extensively cultivated, and where consequently, the rivers, brooks, and marshes were infected during two months of the year, and obstructed during the remainder, by the common method of rotting hemp, and where the women upon whom this task falls, (and they are almost all so employed) are subject from that work to accidents, and to frequent diseases, which bring on premature old age.

But however well convinced M. de Liancourt might be of the excellence of this method, attested by the report of the commission, it was necessary to convince those of its superiority, for whose benefit it was principally designed, and who attend with great reluctance to every project that is new to them, chiefly in rural matters, in which the usual methods are always, in their opinion, the best, and which they think cannot be changed for the better, without the imputation of insanity.

It was necessary, moreover, in making the experiment before the country people, to show to them its easy practicability, its cheapness, and the simple apparatus it required.

M. Molard, who had been one of the members of the commission, charged with the experiment of Mr. Braalle's method, was consulted; this friend to arts and the public welfare, was not contented with giving his advice by letters, but wished to come and preside at the essays of Mr. Liancourt: he did more, he brought to Liancourt, Mr. Braalle himself, the author of the discovery.

All the women of the district were invited to witness the experiment; the judge, and the mayor were also invited. It was necessary to give to the success of the experiment, all the authenticity which circumstances would admit of, and which could only produce the desirable conviction,-a conviction indispensably necessary to produce in that country all the good which was designed.

Here follows the process :

A farm kitchen was the laboratory: the common kitchen boiler was filled with 107 kilogrammes, (220 lbs. French) weight of water, in which 48 grammes (12 oz. French) of green soap were dissolved: ten kilogrammes and three-quarters, (22 lbs. French) of hemp were to be rotted. The imperfection of the apparatus, and the uncertainty of the quantity of soap, inclined Mr. Braalle to think, it was proper to increase the soap a little more than usual; when the water had attained the 80th degree of Reaumer's thermometer, it was poured out into a bad bathing tub, in which the hemp was laid horizontally and pressed with stones, in order to effect the entire immersion; the bathing tub was covered with planks and linen cloths, to confine the heat, and prevent evaporation as far as the imperfect apparatus would per

mit.

Two hours afterwards the hemp was taken out of the tub; and some handfuls distributed among the women; they examined it while very hot, and found it so perfectly rotten, that they could peel it with the greatest ease. The rest of the hemp was put to dry and covered with nets.

The experiment was renewed immediately on the same quantity of hemp; the soapy liquor left in the tub was again returned to the boiler, and three buckets of fresh water, thirty-six gram