An EJJay on Bleaching. 317 



or leaden bent funnel for introducing the fulphuric acid ; i, a 

 leaden cover luted to the neck of the alembic, and pierced 

 with three holes to receive the funnel Z>, the handle of the 

 agitator /:, and the tube /, of three inches aperture, which 

 ierves to conduct the acid gas into the refcrvoir ?n, which 

 performs the office of a Wolfe's bottle : the tube / defcends 

 through the firft aperture mi to the bottom of the refcrvoir, 

 which to two-thirds of its height 13 filled with water. In the 

 refcrvoir m> any fulphuric acid which paffes combines with 

 the water, while the oxygenated muriatic acid traverfes the 

 water, and paffes through the tube n into the condenfer oo> 

 made of wood, in which is placed an agitator /, the arms of 

 which furring the lime water affilts in combining it with the 

 gas in proportion as the bubbles cfcape from the lower ex- 

 tremity of the tube n. The tub has (helves q,q,q, which 

 lerve to oppofe the motion occasioned by the agitator, 

 and thus accelerate the combination of the acid gas. The 

 covering of this tub is fitted to the fides of the tub, as ex-, 

 prefled at r. s is a flop-cock. 



Chaptal's apparatus for bleaching, nearly fimilar to that 

 executed by Bawens. See Plate IV. firft figure, at the top*. 



a the (lair for defcending into the afh-hole n\ b the door 

 of the fire-place p. The flame and fmoke circulate round the 

 boiler i, and pafs through the flue g,g, down under the leaden 

 veffel ft} and then back again to the chimney m. (See ccc 

 the fecond figure, in which a is the ftair to the afh-pit, b the 

 fire-place, dd a winding brick partition to circulate the heat, 

 and ceee the (olid mafon work.) The h (under the arch) is 

 a grate of wood, refling on the edges of the kettle i, contain- 

 ing the bleaching liquor : ee, brick work ; e 1, e 1, (tone work ; 

 q, a conical (lone (topper, which ferves as the lid or cover, 

 perforated, and furnifhed with a fafety valve; the (topper is 

 wrapped round with tow or lint to make it (team- tight : f y a 

 difcharging cock and a regulator to (how the height of the 

 interna! liquor; /, an iron regifter in the chimney m. 



The third figure from the top of the plate is a plan of the 

 apparatus taken on a line with the wooden grate, a, the ftair 

 of the afh-hole; eee, the brick and mafon work; fg>fg* 

 the edges of the kettle built into the mafon work j b 3 i, the 

 wooden grate over the boiler; /, the leaden veffel. 



The other kinds of apparatus have been fo plainly defcribed 

 where their ufes have been alluded to, that any further ex- 

 planation of them here is unnecefiary. 



* Part of the impreflion from the plate was printed off, by miftake, be- 

 fore the numbers were put to the figures ; they are therefore referred to 

 in the order in which they (land, beginning at the top. 



4 XLIX. 0*- 



