Mr Thomas Henry of Manchester began his ex periments on bleaching, by means of oxymuriatic acid, nearly as early as Mr Watt, and without previous knowledge of what he had done. He was very assiduous, and very successful in his trials. At a meeting of the bleachers, held at Manchester, ear ly in 1788, he exhibited half a yard of calico, bleach ed by the new method, which was considered as su perior in whiteness to half a piece of calico, bleach ed by the same process by Messrs Cooper, Baker, and Charles Taylor. In-consequence of this exhibi tion he was applied to by Mr Ridgway of Horwich, to be instructed in the new process. And the in structions which he accordingly received, were the -first step of a series of improvements carried on by Mr Ridgway and his Son, with an ability and spirit of enterprise, which have raised their es tablishment 'to its present extent and importance. (See Annals of Philosophy, VI. 428.) These two gentlemen, Messrs Watt and Henry, had the chief merit of introducing the new mode of bleach ing into Lancashire, and the neighbourhood of•Glas gow.
In the year 1789, M. Berthollet published a me moir on the subject, in the second volume of the Annales de Chimie (p."131). In this memoir, which constituted the first publication on the mode of bleaching by means of oxymuriatic acid, Berthol let gives a detail of the progress of his experiments, and states the attempts that had been made to intro duce the new mode of .bleaching into France. M. Bonjour, who had assisted him in his experiments, associated himself with M. Constant, a manufacturer of cloth at Valenciennes, to form a bleaching esta blishment in that city upon the new plan. But their project was prevented by the prejudices of the inha bitants, and by the jealousy of the bleachers, who were afraid of being injured by the introduction of any new improvements. M. le Comte de Bellaing, .however, who approved of the project, ranted a piece of ground possessed of all the requisite coove nienees ; but rather at too great a distance from Va lenciennes. M. Bonjour applied to the Board of Commerce for the exclusive privilege of bleaching for some years, according to the new method in Va lenciennes and Cambray, and for two leagues around these places, offering at the same time to explain the new process in all its details to those who wished to make themselves acquainted with it. But the re quest was refused.
It does not appear, from Berthollet's account, that the new mode of bleaching had been able to esta blish itself in any manufactory in France, before the publication of his Memoir. One of the great difficulties in the way of applying oxymuriatic acid to bleaching was the very disagreeable and noxious odour which characterizes it, and which rendered it not only very offensive, but highly injurious to the health of the workmen. He describes, at consider able length, a vessel contrived for impregnating water with it, by M. Welter, and likewise the mode of pre paring the gas from common salt, black oxide of manganese, and sulphuric acid. But hisyimprove meats, though considerable, were far from obviating the inconveniences complained of. Some method was wanted which should deprive water impregnated with this gas of its smell, without depriving it of its bleaching qualities. The first attempt to accom plish this object originated from M. Berthollet him self.
When he first began to bleach, by means of water impregnated with oxymuriatic acid, he employed that liquid as concentrated as possible ; but he found that the texture of the cloth steeped in this liquid was considerably injured. To prevent this effect, he at first added a little alkali to the liquid, to saturate a portion of the acid. But he found afterwards that it was better to dilute the liquid with water. Before this last method occurred to him, he was re quested to go to Javelle, to show the bleachers there, the method of preparing the oxymuriatic acid, and making the bleaching liquor. He went twice in consequence, prepared the liquor before the bleach ers, and added some potash to prevent the acid from injuring the texture of the cloth. Sometime after the manufacturers of Javelle announced in the dif ferent journals that they had discovered a peculiar liquid which they called Lessive de Javelle, and which possessed the property of bleaching cloth immersed in it for a few hours. This liquid they prepared by
dissolving potash in the water which they were go ing to impregnate with oxymuriatic acid. The con sequence was, that the liquid absorbed a much greater quantity of gas, and might be diluted with a considerable proportion of water, without losing its bleaching quality.
Being disappointed in their attempts to introduce this liquor among the French bleachers, they came over to England, -and applied to Parliament for the exclusive privilege of supplying the British bleachers with this liquid. The patent was to be given to MM. Bourbollon de Bonnueil and Company. In con sequence of this application, a meeting of the bleachers of Lancashire was advertised, in the be ginning of the year 1788. It was at this meeting that Mr Henry exhibited the half yard of calioo bleached according to the new method. Mr Watt had written a letter to Dr Percival on the which was communicated to the meeting. He stated in it that he had been in possession of a new method of bleaching, by means of oxymuriatic acid, for above a year; that he had learned it from Berthollet, and that he had every reason to believe that the liquor of MM. Bourbollon de Bonnueil and Company, con sisted of oxymuriatic acid, or of some proportion of it. In consequence of this meeting, the county . members of Parliament were requested to oppose the intended monoply. Mr Watt also exerted all his influence ; and Mr Parkes informs us likewise; that one of the Messrs Milnes of Aberdeen, who had been informed of the use of oxymuriatic acid by Mr Copland, happened to be in the gallery of the House of Commons when this application in favour of these gentlemen was made. He took immediate measures to inform the principal members that this was not a new process ; that he himself had long ago prepared an article equally advantageous, and that he was ready to substantiate the truth of his statement when required. (Parkes's Chemical Essays, IV. 62.) In consequence of the united exertions of all these dif ferent gentlemen, the bill was thrown out, and the monopoly prevented. • It seems to have been partly in consequence of this application of the French gentlemen that Mr Henry of Manchester was induced to attempt bleaching in the large way with oxymuriatic acid. His attention had been first drawn to the subject by the papers of Berthollet, published in the Journal de Physique, during the years 1785 and 1786. He was at that time engaged in a course of lectures on Dye ing, Printing, and Bleaching. An acquaintance with the prepprties of oxymuriatic acid, which he had re occasion to exhibit in his course of lectures, and the general hints previously throwu out by Bertliollet, led him to conclude, that the liquor of Bourbollon and Company could be nothing else than oxymuriatic acid, or some compound of it. His first operations on the large scale consisted in ex posing the goods, in a moist state, in air-tight cham bers, to the action of oxymuriatic acid gas. He likewise began to prepare for sale a bleaching liquor, in which the gas was condensed in a very weak so lution of potash ; which, as we learn from Berthollet, was the very same with the Lessive de Javelle. This liquid possessed two advantages over water simply . impregnated with oxymuriatic gas. Its smell was less noxious, and it might be employed to whiten printed calicos without destroying the colours which had been dyed upon the cloth. But these advan tages were much more than counterbalanced by • equivalent disadvantages. It was found not to go nearly so far as water impregnated with oxymuriatic acid, and when kept for some time, it lost its bleach ing properties altogether. The reason of this last alteration is now sufficiently understood ; the oxy muriatic acid in the liquid was gradually destroyed, and converted into common muriatic acid and chlo rin acid ; the water containing merely common mu nate of potash and chlorate of potash. In cons& quence of these disadvantages, the addition of pot ash to the bleaching liquid was soon laid aside.