M. TECHNOLOGY. 513 



and the dye will furnish any shade of good, clear yellow. So 

 far, it has been used chiefly in dyeing wool, its applicability 

 to cotton and silk not having yet been tested. The color 

 washes well, and has been exposed to hot soda solution of 

 two degrees B. without being altered. With other dyes, such 

 as fuchsin, indigo, carmine, perse, etc., it furnishes excellent 

 combinations. 24 C\ 1871, 18. 



WHITE COLOR FOR WOOLENS. 



Reimann's Journal gives a formula for the preparation of 

 what is claimed to be the most beautiful of all known white 

 colors. To prepare this, for each hundred pounds of wool 

 are to be taken three pounds of alum, two pounds of sulphur- 

 ic acid, one pound of cream of tartar, and three eighths of an 

 ounce of anhydrous iodine violet. In this the wool is to be 

 immersed for an hour at a temperature of 104 Fahr. The 

 iodine violet must be bluish, and the quantity to be used will 

 vary slightly in amount with the tone of the desired white. 

 A fresh bath of three pounds of chloride of barium is also to 

 be made, and into this the blued wool is to be introduced 

 and left for two hours, at a temperature of 104 Fahr. The 

 result is a deposit of sulphate of barytes in the wool, which 

 retained a quantity of sulphuric acid from the first bath. This 

 gives to the wool a beautiful white, and increases its weight 

 about 18 per cent. The use of the chloride of barium is, it 

 is said, preferable to the chalking of white goods, and for 

 whitening the wools in question. 24 6 r , 1871, 210. 



DYEING WOOL AND SILK A SCARLET RED. 



A fine scarlet red can be fixed upon wool and silk by means 

 of a process which depends upon the simultaneous applica- 

 tion of naphthaline yellow and fuchsin ; the less the amount 

 of the latter, however, the finer are the shades. A dilute 

 aqueous solution of naphthaline yellow is first to be heated 

 nearly to the boiling-point, and then as much of the solution 

 of fuchsin must be added as amounts to two per cent, of the 

 naphthaline yellow, and the ordinary processes of dyeing are 

 then followed. The two solutions must not be mixed in the 

 cold, as the fuchsin would be precipitated in amorphous flocks; 

 and if the liquid, with its precipitate, is then heated to boil- 

 ing, a part only of the fuchsin will be dissolved, one portion 



Y2 



