706 REPORT—1863. L 
from the balls being subjected to successive washings and drainings. 4th. Use 
of cast-iron decomposing-pans. 5th. Gay-Lussac’s process for! recovering 
and using again the waste nitrous acid in the manufacture of sulphuric acid 
has been adopted by several manufacturers ; others consider that the expense 
of the erections and of working the process may be better applied in pro- 
viding an additional amount of space in the leaden chambers. The special 
improvements are :—1st. Revolving ball furnaces, invented by Messrs. Elliott 
and Russell, of St. Helen’s, and used in the Jarrow Chemical Works. 2nd. In 
the Walker Alkali Works, the waste gas (carbonic oxide, &c.) from the blast- 
furnaces of the adjoining iron-works is conveyed by flues to the evaporating 
and calcining furnaces. The advantage obtained is not only economy of 
fuel, but a hot flame free from smoke and dust, and dispensing with the 
stoker’s labour and tools. It is found very useful for regulating the bottom 
heat of the cast-iron pan in which salt is decomposed. The carbonic oxide 
is, however, found not to burn very well in the presence of muriatic-acid gas. 
Hyposulphite of Soda——The manufacture of hyposulphite of soda has 
largely increased of late years, and we believe it was not made upon the 
Tyne previous to 1838. In 1854 the produce only amounted to 50 tons per 
annum. It has gradually risen to 400 tons per annum. In addition to being 
used in photography, it is largely employed as an “anti-chlor” in paper- 
making; and the markets of Europe and America are chiefly supplied from 
the Tyne. In 1852 Mr. W.S. Losh obtained a patent for the manufacture 
of hyposulphite of soda from soda-waste, which has been the means of 
greatly lessening the price, and extending its application in the arts. On 
account of its great ¢tability, hyposulphite of soda has nearly superseded the 
use of the older salt—sulphite of soda—as an “ anti-chlor,” the latter being 
chiefly confined to sugar-refineries as a deoxidizer. Dr. Jullion has recently 
obtained a patent for the production of hyposulphite of lime, to be used as 
an “anti-chlor,” but it has not yet been introduced in commerce, the appa- 
ratus for its manufacture, in course of erection at the Jarrow Chemical 
Works, not being completed. 
Hydrochloric Acid.—In the decomposition of common salt vast quantities 
of hydrochloric acid are necessarily produced, and it is an important question 
for chemical manufacturers to apply the best means for its condensation. 
Since the visit of the Association in 1838 few branches of manufacture have 
received more attention, and there are few in which greater improvements 
have been effected than in condensing muriatic-acid gas; and this has arisen 
not only on account of the necessity of preventing injury to agriculture, so 
that heavy claims for damage might be avoided, but also in consequence of 
the commercial value attached to hydrochloric acid in the production of 
bleaching-powder, bicarbonate of soda, oxychloride of lead, and other pro- 
ducts. The methods generally employed in condensing are well known, and 
we shall only allude to some of the improvements practically applied. The . 
drying-furnace generally used is called an ‘open furnace,” to which the heat 
of the fire is directly applied; and we believe that the greatest difficulties in 
the way of a perfect condensation, in former times, arose from the gases from 
this furnace. The heat required to drive off the gas from the crude sulphate 
of soda is very great, so that when the gases arrived in the condensers, it 
was found difficult to absorb them, even when a very large quantity of water 
was used; and the muriatie acid which was thus produced was of so low 
a strength, as to be, commercially, almost useless, In former years, also, 
the draught through the condensers was always obtained by a connexion 
with a high chimney ; but in some of the works this plan is now abandoned, 
