256 Advantages of Sulphur et of Lime In Bkaching. 



Probably thofe bleachers who do not at prefent find it convenient to ufe the oxygenated 

 liquor, but continue to bleach by expofure to air, may derive fome advantage from this, by 

 ufing the fulphuret and potafli conjointly or alternately. 



Mr John DufFy of Ball's-bridge (who, from his knowledge of chemiftry, is very well 

 acquainted with the principles of bleaching), was kind enough to repeat the above experi- 

 ments, and his report to me correfponded with my own obfervations. 



It is almod impoffible to afcertain to the full extent, more efpecially by fmall experiments 

 in an elaboratory, the many advantages any fubftance, not hicherto uf;d in bleaching, will 

 afford by varying the mode of application. 



The experimenter docs a great deal by difcovering the efficacy, proving the pradicability, 

 and afcertaining the fafeft and moft economical method of direftly ufnig it, and alfo the beft 

 proportion of it. Before he can arrive at one of thefe, many a round of changes are necef- 

 fary ; indeed a greater number than any man, who is not ufed to experiments, can be aware 

 of. But I (hould hope that the bleacher need not hefitate to ufe it in the ftate in which I 

 prefent it to him, more efpecially as he runs no rifque of injuring the cloth with it. If he 

 can make more of it hereafter, I fliall feel happy upcki the occafion ; no difcovery was ever 

 brought to perfection at once. ■• 



How gradually, and yet how progreffively, the fteam-engine, from Its firft invention by 

 the Marquis of Worcefter, was brought to its prefent degree of perfedion ! Undoubtedly 

 it was juft fo with refpeft to alkalies, the fubftances now ufed by the bleachers; it muft 

 have taken a confiderable time, after their firft application in bleaching, before they could. 

 be made the moit of. 



I will now conclude, by pointing out the advantage Hkely to accrue from the ufe of the ful- 

 phuret to the nation, and alfo the faving to the individual. 



By the information I have had from tlie Cuftom-houfe, it appears that the averao-e im- 

 portation of potafli and barilha the laft twelve years amounts to about 5066 tons annually ; 

 about one half of this (2533 tons) is barilha. The average price of barilha, the laft 

 three years, has been 40 1. a ton ; fo that the value of the quantity imported is 101,323 1. ; 

 of this only half, or thereabout, I underftand, is ufed in bleaching, the remainder being 

 converted into foap, 



Mofl of the pot and pearl-afti is confumed by the bleachers, and the average prfce of it the 

 laft three years has been 65 1. a ton, confequcntly the value of 2,533 ^""^ '^ 164,645.!. 



Hence it feems that the quantity of foreign alkalies imported into the kingdom every year 

 amounts to 265,968 1. ; and that the quantity ufed in bleaching alone amounts to about 

 215,307 1. annually. 



The average price of brimftone for the laft three years is about 25 1. a ton, which is at 

 the rate nearly of two pence farthing a pound; four pounds of brimftone, and twenty pounds 

 of lime,' as already obferved, will produce fixty gallons of liquor. In this country, twenty 

 pounds of lime may be valued at about four pence, fo that the bleacher may have the fixty 

 gallons at the expeuce of is. id. >" 



By 



