juglo:n'e 



By Alvin S. Wheelee 



The American supply of dyes was very suddenly cut off when the 

 Great War began in 1914, and the ports of Germany were blockaded. 

 We were forced to turn to natural dyestuffs and to increase our pro- 

 duction of synthetic dyes. The progress in American manufacture 

 has been so great that the production of dyes in the United States in 

 1917 was nearly equal in total weight to the annual importations be- 

 fore the war. 



NATURAL DYESTUFFS 



The natural coloring matters are very numerous but they are not 

 always fast and their quality is not apt to be uniform. The most 

 important plants which are used as a source of commercial dyestuffs 

 are indigo, logwood, madder, cutch, fustic, turmeric, archil, sandal 

 wood and quercitron bark. There are, however, many other sources 

 of dyes and among these is the walnut hull, long used on the small 

 scale by the thrifty housewife. The coloring matter has great tinc- 

 torial power as any one knows who has removed the hulls from wal- 

 nuts. When these hulls are used and this is still done at the present 

 day, the dye imparted to the goods is a beautiful brown and is very 

 fast. I am told that the dye is also obtainable from the leaves, bark 

 and roots of the walnut tree. The walnut hull contains an aromatic 

 compound called "hydrojuglone which isi a phenol in the naphtha- 

 lene series with hydroxyl groups at positions 1, 4 and 5. Its formula 

 therefore is (I). 



H 



®Ci 



It is with great difficulty solul)le in water, forining a one-half 

 per cent solution at 25°C. It is readily soluble in alkaline liipiids, 

 forming intense yellow solutions. This is most likely the dye wliich 

 has been used so much, especially by the farmer's wife. This hydro- 



