206 ANNUAL OF SCIENTIFIC DISCOVERY. 



cent, of phosphoric acid. Mr. James Hargreaves proposes to 

 utilize this phosphoric acid for fertilizing purposes. The cinder 

 is melted with lime and magnesia, and then roasted. The pro- 

 toxide of iron is converted into a higher oxide, slowly soluble in 

 cold dilute chlorhydric acid, while the phosphate of calcium 

 dissolves readily in this reagent. The cinder may be dissolved 

 in chlorhydric acid directly, and the acid solution treated with lime 

 or chloride of calcium, sufficient to enter into combination with 

 the whole of the phosphoric acid. The mixture is then evapo- 

 rated to dryness and heated to redness to render the peroxide of 

 iron insoluble in chlorhydric acid, and the dry residue treated 

 with acid as in the preceding method. The chlorhydric acid used 

 is utilized as described on page 169. Mr. Hargreaves estimates 

 that 130,000 tons of phosphoric acid are wasted annually in Great 

 Britain in the iron cinder from the furnaces. 



Use of Sulphurous Acid in Bleaching Sugar. A. Seyferth 

 makes use of sulphurous acid for bleaching sugar by mixing in a 

 vacuum pan 100 parts of a concentrated solution of sugar (2S- 

 42 Beaume), with from 3 to 15 parts of a solution of sulphurous 

 acid containing not more than from 1 to 1| per cent, of the acid. 

 The mixture is then concentrated to the proper strength, the 

 whole of the sulphurous acid escaping. The sugar solution thus 

 treated loses completely the peculiar taste generally noticeable in. 

 beet-root sugar. Ber. deutsch. chem, Ges. 



Condensation of the Nitrous Vapors in the Manufacture of Sulphuric 

 Acid. B. Hilman and P. Hart. The vapors are condensed by 

 means of water, wherein lime or magnesia is suspended, and the 

 liquid obtained is either (1) evaporated to dryness and the residue 

 ignited, or (2) heated to the boiling-point with addition of chlor- 

 hydric or sulphuric acid; or (3) evaporated to dryuess and the 

 residue mixed with the residues of the chlorine manufacture -and 

 heated to a gentle red heat; in either case, the nitrous vapors 

 thus obtained are used again in the chambers. 



Dextrine Insoluble in Water. M.Musculus. The author of 

 this paper has obtained a variety of dextrine insoluble in water by 

 the action of glacial acetic acid on starch. This variety of dex- 

 trine is composed of particles of starch which have undergone 

 chemical change with losing their organized structure. These 

 particles are rendered soluble by being heated with water at 

 100 C. for several hours. A similar product may be obtained 

 by boiling the starch with water acidulated with sulphuric acid. 

 This variety consists of little granules, 0.010 to 0.030 ni. m. in 

 diameter, insoluble in cold water, but dissolved without subsequent 

 separation by water at the temperature of 50 C. Comptes 

 Bendus. 



Discrimination of Fibres in Mixed Fabrics. Mr. Spiller treats 

 the fabric with strong chlorhydric acid, which dissolves silk com- 

 pletely and immediately, without appreciably affecting any woollen 

 or lignine fibres with which the silk may have been interwoven. 

 The residual fabric or loose filaments may then be washed and 

 collected, and will be usually without color. A warm aqueous 

 solution of picric acid then applied instantly imparts a warm 



