518" ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



nia will circulate with a waste, which, in case of careful work- 

 ing, will be inconsiderable. 



The soda-ash produced will be very strong and pure, free 

 from alkaline sulphates, sulphites, sulphides, and hyposul- 

 phites, as well as from a variety of other foreign matters now 

 rarely absent. Soda-crystals will be made, as at present, by 

 dissolving soda-ash in water, and allowing it to crystallize 

 at the proper degree of concentration and of temperature. 

 Caustic soda, now prepared from certain residual liquors, 

 technically known as " red liquor," will have to be again 

 made on the primitive method of treating solutions of carbon- 

 ate of soda with slaked lime. The nuisances of hydrochloric, 

 sulphuric, and arsenical fumes will cease. " Vat-waste" will 

 no longer be formed, and the ingenious process of obtaining 

 from it hyposulphite of soda, and for recovering the sulphur 

 it contains, will come to an end. 



The new process, according to Iron, is likely to involve a 

 heavy fall in the price of sulphur and sulphur ores, such as 

 iron pyrites, some of which, especially such as are poor in sul- 

 phur or rich in arsenic, may possibly become unsalable. The 

 supply of sulphuric acid will probably be diminished, and the 

 price increased. Hydrochloric acid, now a waste, and diffi- 

 cult to get rid of, will be utilized, and probably rise in price, 

 as well as bleaching-lime and all substances whose manufact- 

 ure requires the use of this acid. If a commercial success, 

 according to the authority indicated, chemical manufactures 

 will undergo such a change as has rarely before been witness- 

 ed. 3 A, October 18, 1873, 485. 



NEW METHOD OF MAKING PAPER PULP. 



Mr. Keegan's new process for the manufacture of paper 

 pulp from wood consists mainly in separating the ligneous 

 fibres by means of an alkali. Soft wood, as, for instance, pine, 

 is first cut into little tablets, from six to twelve inches long 

 and half an inch thick. Uniformity of size is desirable, as in- 

 suring uniform rapidity of action upon the different pieces. 

 These tablets are placed in a cylindrical vessel mounted on a 

 horizontal axis, which revolves slowly during the operation. 

 A solution of caustic soda of about 20 is next admitted to 

 the wood, the vessel is hermetically sealed, and then, by means 

 of a powerful pump, the liquid is completely injected into 



