708 REPORT—1863. 
A patent was obtained by Mr. R. C. Clapham, in 1860, for the use of the 
weak acid in the place of water for condensing, which has been successfully 
carried out in the above works; and it will thus be seen that the whole of 
the acid produced was obtained and calculated without difficulty. Muriatic 
acid is not entirely free from impurities ; and, on account of its containing 
arsenic, iron, sulphuric acid, &c., it is not applicable to all purposes, ‘The 
total quantity of hydrochloric acid produced is about 180,000 tons per 
annum. 
Manganese.—Manganese is imported from Germany and Spain, but it is 
chiefly from the latter country that the richest ores arenow obtained. It is 
found in hills consisting of schistose rock, which sometimes rise to a height 
of 800 feet from the level of the plain; but it is also found in “ pockets,” 
in which case it is quarried by picks, and occasionally gunpowder is used, 
The quality of the ore varies from 50 to 90 per cent. peroxide; and to 
obtain the richer ore, men and boys are employed to break and sort it. It 
is then put into sacks and carried a distance of 20 to 35 miles, on mules’ 
backs, to the ports of shipment in the Mediterranean. The richest ores are 
obtained at Calanas, in the province of Huelva, 30 miles north of the ancient 
Roman fishing-town of Huelva. We are indebted to Mr. 8. F. Gething for 
this information, who also informs us that he imported to the Tyne, in 
1857, the first cargo of this kind of manganese. Manganese ore frequently 
contains peroxide of iron, copper, cobalt, titanium, &e.; but no means have 
hitherto been taken to separate them. Manganese is used in the manufac- 
ture of glass, iron, and of bleaching-powder ; and for the latter it is imported 
to the extent of 14,400 tons annually. Several patents have been taken out 
for the recovery of the manganese from the waste chloride of manganese 
solutions, but generally with indifferent success. The most successful, how- 
ever, is the process of the late Mr. Charles Dunlop, of Glasgow, in which the 
manganese is precipitated as a carbonate, and finally oxidized. This patent 
has been profitably worked at St. Rollox, in Glasgow, and has, to some 
extent, superseded the use of native manganese. Still more recently, a 
patent has been obtained by Mr. Clapham for the separation of the free 
hydrochloric acid contained in the waste manganese solutions, and for its 
application in the manufacture of bleaching-powder. 
French Limestone, locally called ‘ Cliff? is imported as ballast from the 
Seine, and also from the coast of France, to the extent of about 14,000 tons 
annually. It forms part of the upper chalk-bed in the secondary deposits, 
and is nearly pure carbonate of lime; and although very like chalk in its 
appearance, differs from it to some extent in being compact, harder, and less 
susceptible of retaining water. It is always used in this locality, in prefer- 
ence to other limestone, for making bleaching-powder. 
Bleaching-powder.—Since 1831, the method pursued in the manufacture 
of bleaching-powder has entirely changed, and the quantity made has far 
more than doubled. At that time it was made by the decomposition of 
manganese and common salt with sulphuric acid, which was rather a costly 
process, and the price was about £28 per ton. Itis now manufactured from 
what was, at one time, the waste muriatic acid referred to above, and the 
price has been reduced to one-third. During the last few years the demand 
for bleaching-powder has been increased, partly on account of the extensive 
use of Esparto grass from Spain in the manufacture of paper, which has been 
found to require a large quantity of chemicals to bleach it. The quantity of 
bleaching-powder now made is 11,200 tons per annum. 
Soap.—The first soapery in this locality was begun by Messrs. Lamb and 
