440 BROOKS. 



Since hemp, pineapple, and ramie fibers are dyed with difficulty, colored 

 threads of cotton or silk are often woven into the cloth. Large quantities 

 of goods made in this way are barred from free entry into the United 

 States since the cotton and silk do not originate in the Philippines. 



The careful selection and use of the best synthetic dyes which have been 

 shown to be particularly adapted to hemp and other hard fibers would 

 undoubtedly be a benefit to the industry. So far as I have been able to 

 ascertain, the employment of Turkey-red oil and tannin-antimony 

 mordants and the developed colors, such as those obtained from primu- 

 line, is unknown. 



The coal-tar colors handled by the Chinese traders are invariably cheap and 

 easily applied. Eosin, fuchsin, rhodamine, methylene blue, and malachite green 

 are probably the most common. Perhaps because of their brightness they have 

 found favor with the Filipinos as many of these cheaper coal-tar colors quickly 

 fade in the sunlight. 



THE ACTION OP LIGHT ON NATURAL AND SYNTHETIC DYES. 



In a report 3 on the action of light on dyed colors a committee of the British 

 Association, Section B, states that annatto and turmeric fall among the class 

 of the most fugitive dyes, the color almost disappearing in three weeks while 

 old fustic from Ghlorophora tinctoria Gaudieh. (Morus tinctoria L.) showed very 

 marked fading in thirty days. The fugitive character of many natural dyes is 

 readily understood in view of the phenolic character of the majority of them. 

 Thus Gebhard 4 has recently shown that in the alizarine series the introduction 

 of hydroxyl groups increases the sensitiveness to light. 



J. J. Hummel 5 states that turmeric, catechu and indigo carmine, on wool, 

 are quickly faded, and Brazil wood and young fustic on all mordants. Old fustic, 

 weld, quercitron bark and Persian berries give fast colors on chromium, copper 

 and iron mordants, but are fugitive on tin and aluminium. The fugitive char- 

 acter of the natural dyes is much more marked when dyed on cotton than on 

 wool or silk. The madder colors on Turkey-red. oil and logwood on iron and 

 tannin are undoubtedly the fastest of the group. 



I exposed several of the more common natural dyes to the direct sun- 

 light of this locality. Cotton deeply dyed with turmeric faded entirely 

 in four days. For comparison, samples of wool dyed with eosin, rhoda- 

 mine, methyl violet, Bismarck brown and orange II were exposed with the 

 natural dyes. Turmeric was faded more quicldy than eosin, one of the 

 most fugitive of the coal-tar dyes. The yellow dye, berberine, turned 

 to a brown tint and was not faded after two months' exposure. The 

 brown khaki shades from ipil (Intsia tijuga 0. Ktze.) and tangal wood 

 (Ceriops iagal C. B. Eob.) were fast, no change being noticeable in two 

 months, while Bismarck brown was destroyed almost entirely in the same 

 time. The other dyes behaved as described by Hummel, save that all 

 faded a little more rapidly in the sunlight of the Tropics. 



'Journ. Soc. Chem. Ind. (1894), 13, 803. 

 i Ztsohr. f. ang. Chem. (1909), 22, 1890. 

 *Joum. Soc. Chem. Ind. (1891), 10, 832. 



