440 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



a soft mass and kept warm. After the lapse of several hours 

 nine ounces of oxalic acid are to be added, and the whole com- 

 position is to be suspended for some time in a kettle of boil- 

 inu: water. It is then to be diluted with water according: to 

 the shade desired, in which about three per cent, of gum is dis- 

 solved, and the fabrics to be dyed immersed in it, and the 

 whole, still thoroughly wet, are to be transferred into the 

 steam box, where they are to be left for ten minutes to the 

 action of the steam. The color becomes perfectly fastened, 

 and rinsing removes the adhering gum, etc. 11 C, xi.,84. 



MORDANT FOR FASTENING ANILINE COLORS IN COTTON YARN. 



As a mordant for thoroughly fastening aniline dyes upon 

 cotton yarn, Mr. II. Knal recommends a mixture of solutions 

 of three pounds of sugar of lead in twenty-four pounds of hot 

 water; three pounds of potash in the same quantity, and six 

 pounds of alum in forty pounds of water. This liquid is to 

 be diluted still more before being used. The yarn to be 

 dyed (about 20 pounds) is allowed to remain in the solution 

 twelve hours, and, after being thoroughly wrung out, is to be 

 placed for one hour in a bath of chloride of tin. Rinsing in 

 clear water, and wringing, finishes the preparatory operations. 

 The process of dyeing is performed by placing the yarn in a 

 cold bath, to which a solution of three ounces of aniline red 

 in six pounds of alcohol of 96 per cent, is to be added. This 

 is then slowly heated to boiling, and kept for several minutes 

 at this temperature, when the yarn may be taken out, rinsed 

 and dried. 13 C, 1871, v., 329. 



ADULTERATION OF ANILINE COLORS WITH SUGAR. 



Mr. Joly, of the University of Brussels, has ascertained 

 that red aniline colors, such as fuchsin, rubin, etc., are fre- 

 quently adulterated with great quantities of sugar, even to 

 the amount of 50 per cent. On treating a sample of the sus- 

 pected dyestuff with absolute alcohol, or, still better, with a 

 mixture of alcohol and ether, the sugar will be left undis- 

 solved, and the amount of fraudulent mixture thus shown. 

 12 (7, iv., 30. 



ADULTERATION OF COCHINEAL. 



There is a certain kind of cochineal in market which has a 



