An BJfay o?i Bleaching. lol 



varnifhed iron (to prevent Tufting) of a pretty considerable 

 height, terminating at top with a Wolf's bottle, the bottom 

 of which muft be taken out, and which is to be placed in a 

 collar formed in the leaden cylinder; care being taken to 

 cement it with a luting of wax to render it impermeable to 

 fluids. This capital of glafs will enable the operator to fee 

 the quantity of air bubbles difengaged from the furfaee of the 

 water, and thus to appreciate the progrefs of the faturation, 

 while the weight of this narrow and high column of water 

 prefTing on the bubbles of fulphurous acid gas, in proportion 

 as it is difengaged from the extremity of the tube at the bot- 

 tom of the cynnder, will facilitate its combination with the 

 water, and accelerate its folution in that fluid. That nothing 

 may be loft, two or three of thefe cylinders can be united in 

 the fame way as is done with a feries of Wolf's bottles. A 

 cock adapted to the bottom of each cylinder will facilitate 

 the difcharge into the immerfing tubs. 



The apparatus which we would employ for the immerflon 

 of woollen and filk (tuffs in leys of fulphurous acid are per- 

 fectly flmilar to that which we mall defcribe hereafter for 

 immerfion in oxygenated muriatic acid, and which we have 

 conftructed according to the principles of Rupp *. It was 

 by reafoning upon his apparatus with C. Widmer, of Jouy, 

 that we conceived the defign of the prefent one, which is 

 now making at the manufactory of Effone. Let us fuppofe 

 an oblong box, divided in the middle by a partition, and on 

 each fide of it a large reel, on one of which the ftuff is rolled 

 up: in each angle are placed rollers, over which the (tuff is 

 conveyed before it panes the partition, and traverfes a like 

 number of rollers, which conduct it to the other reel. The 

 object of this difpofition is to caufe the fluffs to pafs through 

 the bleaching ley, and to expofe to its action the greater!, 

 furfaee poffible. 



To turn thefe reels, an axis or column of glafs pairing 

 through a collar of leather is employed. One of the extre- 

 mities of this axis, which is fquare, is inferted into the axis 

 of -the reel, while the other is adapted to a handle, which 

 gives it a rotary motion. By this difpofition there is no need 

 ior employing any metallic Jubilance internally. To prevent 

 the difperfion of the gas, the covering of this apparatus is fur- 

 niibed with a border which fits exactly into the box, and of 

 which an inch^ at leaft, ought to be immerfed into the de* 

 terfive liquor. 



* For an account of Mr. Rupp's procefs and apparatus here alluded to, 

 tic Mancheflcr Tranfaftions, vol. v. j or Philosophical Magazine, vol. ii. 



— Efi>JT, 



G 3 For 



