158 
Bleaching of 
the vessels I shall be very exact — the depth of the still is 2 feet $ 
inches ; the diameter 2 feet 3 inches ; the cavity where the lid 
fits is 1 3 inches deep ; the proportions of the intermediate vessel 
are 16 inches long, 12 inches broad, and 1 1 high ; the reservoir is 
in depth 20 inches, diameter 4 feet 8 inches ; the consolidating ves- 
sel which dips in the water is 1 4 inches square, 7 inches high at 
the top, and the lid has two handles to take it off. When you 
are going to put in the lime water, the cap of the still is elevated 
by apuily, which at the top of D° you see a hook made fast to D* 
for the same purpose, to put it on and take it off without any far- 
ther trouble. The still is laid in a metal boiler, and underneath the 
still is 4 inches of sand, but the body is a cavity all round to the 
top which is inclosed with brick work ; the whole apparatus is lead, 
N. B. The reservoir is also lined with lead, as also the cistern 
which the old lees is thrown into. The reservoir is a wooden ves- 
3ek and, as I said before, lined with sheet lead. J. K. 
REMARKS. 
I am obliged to Mr. Cist for this communication, which bears the 
marks, tho’ rough, of practical experience. But the proportions of I 
the materials are not accurately adjusted. Twenty one gallons of sa- 
turated salt brine will not contain quite 60lbs. of salt, for 16 ounces s 
or a pint of water, will not quite dissolve 6 ounces of salt. Hence 
the proportions here, are salt 105 lb. manganese 90lb. oil of vitriol II i 
i26ib. water 160lb. But the best proportions are, by weight, salt < 
8 parts, manganese 3 parts, oil of vitriol of commerce (weighing 
29 1-2 ounces to the wine pint) 6 parts, water 12 parts. So that 
to 1 1 2lb. of salt, there should have been about 50lb. manganese, :,! 
and 80lb. oil of vitriol. These are the common proportions of the j 
bleachers in Manchester. The receipt of Mr. Cist’s correspondent f 
is therefore wasteful in the dearest of the articles. If there should 
be a little less oil of vitriol, nothing is wasted but the salt, which, in 
this country, is of little consequence comparatively. 
There have been two or three patents for bleaching paper in 
England. I know not how they succeeded. I shall have occasion 
to detail what I know on the subject of bleaching generally in a 
future paper. But as the present communication is entitled loan 
insertion, and the subject is before me, I shall give, for the pre- 
sent, the following process, which I am firmly persuaded is of 
much more importance than any thing that has hitherto been pub- 
lished on the subject. It has been already published in Dr.. 
