1227
Mug
deals which strengthen the chamberThe edges of the holes are bevelled outwards, so as to fit a large conical
°l ) 6rt it " 00 ^ faced with lead, called a man-hole door. One or other of these doors isir, eil et * from time to time, to allow the superintendent to inspect the process, or work-The -°. enl er, after the chamber is well ventilated, for the purpose of making repairs.tli e or tie-beams, that bind the rafters of the roof of both the leaden chamber and
ttteir ° U j e ’ Inust be at least 7 inches deep, by 3 broad, and of such length as to havea njjJ?® 8 supported upon the outer wall, or the columnar supports of the roof, in casebe am ^ of chambers are enclosed together in parallel ranges under a vast shed. TheseSo , de ;> Which lie two feet apart, suspend the leaden roof, by means of leaden strapstii Cail to its upper surface and edges. The sides of the chamber are sustained bythiclj S s * m *Iar leaden straps affixed to the wooden posts (uprights), 4 inches broad by 3kclovv ^ ace d two or three feet apart along the sides of the chamber; resting on the ground'b at a "d mortised into the tie-beams above. Some chambers rest upon a sand-floor ;°l )f n a,e Pccfrfably placed upon wooden joists, supported by pillars stretching over anth e bot^*’ 8S in the figure, into which the workmen may descend readily, to examine
Tl,
on the top of the chamber, is sometimes joined to a long pipe of lead laidc ° n den .‘ Z0ll tally, with a slight inclination upwards, along the roof, for favoring the. 8at ion and return of acid matter.
20 fe„f ex tremity l, of the chamber, which, having a downward slope of 1 inch in everya « ; n should stand from 3 to 6 inches (according to its length) lower than i, one leg ofWill sh e «ed syphon pipe is fixed by fusion, into which the liquid of the chamber passing,that b ° W ^ *t s altilude the depth on the bottom within. From the cup-shaped orifice ofthe o ant - u P pipe, the acid of the chamber is drawn off by an ordinary leaden syphon into’fb e c ® n tration pans.
Per s S lee t lead of which the sides and top are made should weigh from 5 to 6 poundsH ' are foot; that of the bottom should he nearly of double thickness.
«han n ln " now detailed, with sufficient minuteness, the construction of the chamber, Iin axt describe the mode of operating with it. There are at least two plans at present ■°n tb e , burning the sulphur coutinuously in the oven. In the one, the sulphur is laid1 u rt k e, (or rather on the flat hearth in the separate oven, above described,) and isl he g b 5' a slight fire placed under it; which fire, however, is allowed to go out after^ ai »es t because the oven becomes by that lime sufficiently heated hy the sulphurW? ea rry on the subsequent combustion. Upon the hearth, an iron tripod is set,nitr 8 a few inches above it, a hemispherical cast-iron bowl (basin) charged with°f br„- a lts decomposing proportion of strong sulphuric acid. In the other plan, 12 partsstr 0n „ ls *i sulphur, and 1 of nitre, are mixed in a leaden trough on the floor with 1 of‘he hot h Ulphu, 'ic ac ‘^’ an( i ( b e mixture is shovelled through the sliding iron door upon*i«e of , 1 aai ' t b- The successive charges of sulphur are proportioned, of course, to thefrigh hi e chamber. In one of the largest, which is 120 feet long, 20 broad, and 16
1 ' *■<, r- - w - - -
l QUr' are burned in the course of 24 hours, divided into 6 charges, every fourth
^ cwts. each. In chambers of one sixth greater capacity, containing 1400
first i Cube , 1 ton of sulphur is burned in 24 hours. This immense production was
t'he bnf°^ Uce ^ at Chaunay and Dieuze , under the management of M. Clement-Desormes.aci d J ton > of the chamber should be covered at first with a thin stratum of sulphuric
S s Pec. grav. 1-07, which decomposes nitrous acid into oxygen and nitrous gas;*betn f ' v dh more water, which would absorb the nitrous acid vapors, and withdraw‘he nit rom their aerial sphere of action. The vapor of nitric acid, disengaged fromsulphj* on ‘he hearth of the oven, when brought into intimate contact with the“ into ° ,ls ae >d, either gives up oxygen to it, becomes itself nitrous gas, and converts■° I)l Pou l * * * S a Ulphu,ic ncid; or combines with the sulphurous acid into the crystalline“Jto sulh a .b° v 6 described, which, tbe moment it meets with moisture, is decomposedh le! y r Ufic ac ‘ d and nitrous gas. The atmospherical oxygen of the chamber imme-lll e Co ec °uverts this gas into nitrous or nitric acid fumes, which are again ready, with°f byd r pera ‘ion of sulphurous acid gas and aqueous vapor, to produce fresh quantitiesc ttriou s ? s su lphuric acid (oil of vitriol) and nitrous gas. At low temperatures, thisa f*4 to a* a -' °f chemical affinities has a great tendency to form the crystalline compound,fMes of epos ‘te it in a crust of considerable thickness (from one half to one inch) on thebifid 0c he uhamber, so as to render the process inoperative. A circumstance of this. filio) j n V1 |) le, b ' n a very striking manner, during winter, in a manufacture of oil oftailed Kussia ! and it has sometimes occurred, to a' moderate extent, in Scotland . ItV^tain’ at Marseilles , tlie maladie lies chamkres. It may be certainly prevented, byv atl th* 11 * t ' le ‘ n,ei '‘ or of the chamber, a jet of steam, at a temperature of 100° F.u^itnt Jr e cr 5'sta!s fall into the dilute acid at the bottom, they are decomposed with a■ fe,^ ervescea oe, and a hissing gurgling noise, somewhat like thatofatun of beer inwirnentation.