M. TECHNOLOGY. g03 



solution of acid sulphite of soda, then stirring in dilute hy- 

 drochloric acid (fifty parts of water to one of acid), covering 

 the vessel, allowing it to remain a quarter of an hour, and aft- 

 erward thoroughly rinsing the articles. 26 C, 1873, 166. 



PRESERVATION OF TEASEL-CAKDS. 



Teasel-cards, for dressing cloth, may not only be rendered 

 tougher, more elastic and durable, but adapted to working 

 under water, by impregnating them with a solution of about 

 six pounds of sulphate of copper in two hundred and fifty 

 pounds of water. Sulphate of zinc may rej^lace sulphate of 

 copper. 5 (7, 1873, 224. 



CANNELLE, A NEW BKOWN ANILINE DYE. 



An aniline, called cannelle-brown, suitable for replacing 

 dye-woods in producing, on silk, wool, or cotton, a beauti- 

 ful, bright wood-brown, and all shades of brown, with less 

 trouble, and not too great expense, has been prepared for some 

 time by Knosp, of Stuttgart. For silk and wool no mordant 

 is necessary, the dye being simply dissolved in hot water, 

 and filtered through flannel, when cold. Silk is dyed in a 

 lukewarm bath with which this solution is mixed, and slight- 

 ly acidified with tartaric acid. The color can be deepened 

 and tinted by the addition of a solution of patent or methyl 

 violet, or precipitated indigo. Wool is dyed in a boiling 

 bath, with the addition of half a pound of Glauber's salt, and 

 one eighth of a pound of sulphuric acid to ten pounds of 

 wool ; for shading and tinting, the same dyes may be used as 

 for silk, the cheaper precipitated indigo being preferable. 

 Cotton must be mordanted (best with tannin), by using three 

 pounds of sumach, or a quarter of a pound of good tannin, to 

 ten pounds of cotton. It is then dyed in the usual way in a 

 cold bath of pure cannelle. 5 (7, 1873, XXYI, 206. 



A NEW DYE-STUFF. 



Now that all possible shades of color have been produced 

 from aniline, chemists have turned their attention to anthra- 

 cene and alizarine ; and Si^ringmuhl obtains an accessory prod- 

 uct in the artificial manufacture of alizarine out of anthra- 

 cene, frohi which a beautiful blue can be made, superior in 

 many respects" to all aniline blues. Dried in a vacuum, it 



