MECHANICS AND USEFUL ARTS. 85 



solution consumed by the above process will be about thirty to forty 

 gallons for every hundred weight of fibre, and of hypoehlorite about 

 25 per cent, of the weight of fibre. The hydrate for the alkaline 

 solution may be obtained by dissolving soda or potash in lime water, 

 and decanting the clear liquor; and the hypoehlorite of alumina for 

 the bleaching process by dissolving sulphate of alumina in a solution 

 of hypoehlorite (common chloride) of lime. The Avaters obtained by 

 the first process when evaporated, yield a resinous soap, which may be 

 mixed with other materials, and burnt as fuel, or used in the unmixed 

 state. The above process is applicable also to flax waste, cotton waste, 

 hemp, tow, &c., but does not supersede the necessity of first converting 

 these materials into half stuff. 



The second part of the invention consists in treating wood shavings 

 (pine, ash, elm, and beech are suitable for this purpose) with nitric 

 acid in order to obtain therefrom a pulp to be used in the manufacture 

 of paper. 



In carrying this part of the invention into effect, the patentees em- 

 ploy two vessels in connection with each other, having perforated false 

 bottoms on which the shavings to be operated on are placed in a damp 

 state, and pressed. About 80 per cent, by weight of white nitric acid, 

 (of a strength of 36 Baume,) diluted to about 5 or 6 Baume, is then 

 added to the shavings in one of the vessels, and after standing about 

 four hours, heat is applied until ebulition commences, and . nitrous 

 fumes are evolved. These fumes are caused to pass into the second 

 vessel, where they come in contact with the damped shavings, and are 

 partially converted into hyponitric acid. When the boiling has been 

 continued for a sufficient time, the shavings are subjected, for about 

 two hours, to the action of solution of hydrate of potash or soda, of a 

 strength of about 2 Baume, in the manner before described, are 

 washed, and they are then bleached by hypoehlorite of alumina, using, 

 however, only about two per cent, by weight of the materials in mak- 

 ing the solution. This last operation, with the aid of subsequent 

 washings, converts the shavings to a state of half stuff, which may be 

 used atone or with rag pulp, according to the usual methods. The 

 acid liquor employed in operating on the first batch of shavings, after 

 having about 40 per cent, of the weight of the materials added to it, is 

 used for treating another quantity, the nitrous fumes evolved being 

 applied as before described. By evaporating the used acid liquors, 

 oxalic acid may be obtained, as well as an acid of a character analogous 

 to nitropicric acid. 



PAPIER-MACHE. 



ME. C. BIELEFELD, of London, has obtained a patent for the man- 

 ufacture of papier-mache, of which the following is a description, as 

 given in Newton's Patent Journal. " Sheets of papier-mache, of 

 considerable thickness, have been commonly produced by causing 

 numerous sheets of paper to be successively pasted together and dried, 

 until the required thickness of sheet is obtained. The desired thick- 



