116 REPORT— 1861. 



der and bleaching-liquor, both of which products are made in large quantities 

 in the district, 155 tons of bleaching-powder* being made each week. 

 The only points in this manufacture which call for remark are : — 



(1) An ingenious process for preparing chlorine without the use of 

 binoxide of manganese is used by Mr. Shanks of St. Helens. The process is 

 as follows : — Hydrochloric acid is added to chromate of lime, sesquichloride 

 of chromium and free chlorine are produced, and the free chlorine is used 

 for making bleaching-powder. Then lime is added to the sesquichloride of 

 chromium, and the precipitated sesquioxide reconverted into chromate by 

 heating with lime in a reverberatory furnace. 



(2) The regeneration of peroxide of manganese from the waste liquors 

 containing chloride of manganese has, as is well known, been performed with 

 success by Mr. Charles Dunlop, so much so that the product obtained is 

 almost pure. Dr. Gerland of Newton-le-Willows has communicated to us the 

 following process for recovering from these liquors not only peroxide of 

 manganese, but also the nickel and cobalt which they contain. The liquors 

 are first neutralized with limestone, and then caustic lime is added until all 

 the iron is precipitated as hydrated peroxide of iron. The precipitate, after 

 washing and drying, may be used as yellow ochre. The filtrate contains 

 manganese, nickel, and cobalt. The two latter metals are precipitated as 

 sulphides by means of a solution of sulphide of calcium (obtained from black- 

 ash waste), which is added until the precipitate ceases to be of a pure black. 

 The precipitate is now collected and subjected to the well-known manipula- 

 tions for separating the metals. The supernatant liquid is siphoned ofl", and 

 the manganese contained in it is precipitated as hydrated protoxide by adding 

 milk of lime. The oxide is washed by decantation and thrown on calico for 

 draining. It is converted into the higher oxide simply by the agency of 

 heat and air, and is generally obtained as a fine black powder containing 

 70 per cent, of peroxide. The average quantity of cobalt contained in 1 ton 

 of manganese is 10 lbs., and of nickel 5 lbs. 



IV. Chlorate of Potash. 



From 4 to 5 tons of this salt are manufactured weekly in this district. 

 It is employed for making matches, and also as an oxidizing agent in steam 

 colours on calico. 



V. Hyposulphite of Soda. 



This salt is manufactured by Messrs. Roberts, Dale and Co., to the extent 

 of 3 tons weekly. It is prepared by passing sulphurous acid through a solu- 

 tion of sulphide of sodium, and purified by recrystallization. It is used by 

 paper-makers, by photographers, and by bleachers (known as antichlor). 



VI. Silicate of Soda. 



The experiments of Fuchs, Kuhlmann, and others have shown that the 

 alkaline silicates may be employed with success for the purpose of coating 

 building-stones of a soft or porous nature, thus enabling them to resist 

 the action both of air and water. Another use has been found for them 

 in this district, viz. as a substitute for cow-dung in calico-printing ; and they 

 are also extensively employed by soap-manufacturers in place of the resinates. 

 Silicate of soda is the compound employed. The process of manufacture is 

 simple. Sand and carbonate of soda are melted together, a sufficient quan- 



* Of this quantity 70 tons are produced at St. Helens, 40 at Runcorn and Runcorn Gap, 

 and 45 in Flint. 



