1892. | NEW YORK ACADEMY OF SCIENCES. 157 
The Natural Dyes as Applied to Wool. 
BY H. T. VULTE AND D. W. WARD. 
The work described in this brief memoir was undertaken some 
five years ago, and from causes unseen at that time the publication 
has been delayed until the present. 
As originally designed, the work was merely the preparation of 
a large series of samples of wool dyed with various natural dye- 
stuffs and common mordants as an exhibit of this branch of the 
dyer’s art now rapidly going out of use. 
During the prosecution of the work it was seen that a valuable 
comparative method of testing these dyes might be evolved from 
the facts as recorded in the results of these tests. 
The samples were prepared from pieces of woollen flannel of known 
purity weighing ten grams each, washed, mordanted in the proper 
baths, washed again, and dyed in a bath of the dye carefully pre- 
pared, the conditions differing with the various dyestuffs. 
225 samples were made, with 5 mordants, the list including the - 
following dyestuffs :— 
Brazil-wood, Catechu, 
Peach-wood, Quercitron, 
Lima-wood, Barberry root, 
Bar-wood, Sumach, 
Sapan-wood, Saffron, 
Cam-wood, Weld, 
Hypernic, Fustic, 
Cudbear, ; Turmeric, 
Cochineal, Persian berries, 
Madder, Logwood, 
Anatto, Tannin. 
Lac, 
The method proposed for testing or valuation of a dyestuff is 
briefly as follows :— 
For instance, logwood: Ten grams of flannel are mordanted with 
alumina sulphate for one hour at 212° F., then cooled, washed, and 
divided in two equal parts; one part is dyed in a 10 per cent. bath 
of standard chips for one hour at 212° F. and the other part in a 
10 per cent. bath of the. logwood to be tested under the same con- 
ditions. The two pieces are finally removed from their respective 
baths, dried, and compared as to shade. It is well to have a few 
samples of 1, 24, and 5 per cent. standard dye for comparison. 
With a little practice the shade may easily be matched within 1 
per cent. It is best always to choose the brilliant shades for com- 
parison. I have had no difficulty in keeping standard samples, 
provided they are protected from strong sunlight. 
The following formule used in these tests will be found inter- 
