132 CHEMICAL MANUFACTURES ON THE TYNE. 



liquor, and thus escape the partial decomposition and consequent forma- 

 tion of sulphuret ' which resulted from the halls being subjected to suc- 

 cessive washings and drainings off. 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 erec- 

 tions and of working the process may be better applied in providing an 

 additional amount of space in the leaden chambers. Special improve- 

 ments. — 1st. Eevolving ball furnaces, invented by Messrs. Elliott and 

 Eussel, of St. Helen's, and used in the Jarrow Chemical Works. (See 

 Jury Eeport by Dr. Hofmann.) 2nd. In the Walker Alkali Works the 

 waste gas (carbonic oxide) 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. For easily regulating the bottom heat of the cast iron pan in 

 which salt is decomposed it is found very useful. The carbonic oxide 

 is, however, found not to burn very well in the presence of muriatic 

 acid gas. 



Hyposulphite op Soda. — The manufacture of hyposulphite of soda 

 has largely increased of late years, and we believe in 1838 it was not 

 made at all upon the Tyne. In 1854 the produce only amounted to 50 

 tons a-year. 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 from the Tyne the markets of Europe and 

 America are chiefly supplied. 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 consequently extend- 

 ing its application in the arts. On account of its greater stability, 

 hyposulphite of soda has nearly superseded the use of the older salt of 

 sulphite of soda as an " anti-chlor," the latter being chiefly confined to 

 sugar refineries as a deoxidiser. 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, being not yet 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 con- 

 densing 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 



