Prof. Schweizer on q Solvent for Cellulose. 523 



sand was taken. The regulus had indications of a lamellar cry- 

 stalline structure, and a colour slightly inclining to yellow. It 

 contained 11 per cent, of silicon. 



Brunner had found that manganese prepared by his process, 

 without the intentional addition of silicon, contained from 0"6 to 

 6*4 per cent. ; and in one preparation in which siiicofluoride of 

 potassium was added, a regulus was obtained containing 9*86 

 per cent, of silicon*. He found that the proportion of silicon 

 may be diminished by mixing the regulus in coarse powder with 

 twice its weight of chloride of sodium, to which 1 per cent, of 

 chlorate of potash had been added, and keeping the mixture for 

 a few minutes at a white heat. In this manner the silicon is 

 oxidized and passes into the slag, and the proportion of silicon 

 is diminished to 0-1 per cent. But the metal thus prepared is 

 not sensibly altered either in colour, hardness, fusibility, or 

 lustre ; and Wohler is inclined to think that even such a small 

 proportion of silicon is sufficient to alter the properties of the 

 metal, especially as the diiFerent kinds of iron — bar iron, steel, 

 and cast iron — show something similar. 



Schweizer found t that ammoniacal- solution of oxide of copper, 

 prepared by dissoMng hyposulphate of copper or basic sulphate 

 of copper in strong ammonia, has the property of dissolving vege- 

 table fibre even at ordinary temperatures. Cotton immersed in 

 the liquid soon becomes gelatinous, and finally dissolves-up to an 

 almost clear blue solution, wilich when much diluted with water 

 may be filtered. Hydrochloric acid added to this solution preci- 

 pitates a voluminous white mass, which appears to be disinte- 

 grated but not essentially altered cellulose. Paper and linen 

 also dissolve, but more slowly. Silk dissolves even more rapidly 

 than cotton ; and acids precipitate from the filtered solution a ge- 

 latinous mass. Wool is only dissolved when heat is applied. Hair 

 swells up without dissolving. Bladder at first swells up, and 

 then dissolves. Starch merely swells up, but inuline dissolves. 

 CramerJ investigated the deportment of Schweize<i''s reagent 

 towards cellular membrane, starch, inuline, and cellular nucleus, 

 and found Schweizer's observations confirmed. He also ob- 

 served that the solvent ]n-o]jerties of the solution are diminished 

 by being kept long, and also by the frequent access of air. 



Schlossberger§ has recently observed that ammoniacal solu- 

 tion of oxide of nickel has the property of dissolving silk, and, 



* Pof^jjendorflF's Annalen, vol. ciii. p. 1.'19. 



t Journal fiir Prukl. C/u-mte, vol. Ixxiii. p. 10i>. Clieiiiicul Gazette, 

 vol. xvi. |). 'i'i. 



X JoiinialfiJr Praht. Cliemie. vol. l.wiii. |). 1. 

 § l>iLl)i}r'K Aitinilen, July lt<i>H. 



