300 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. [6] 



this decoction a brownish color, which, by the repeated alternations of 

 water and air, is in a little time discharged, whilst the fine glossy brown 

 communicated by the same means to sillcen nets permanently resists 

 both the air and the water, and stands as long as the animal filaments 

 themselves." 



Tannin of one kind or another is actually employed by dyers, not so 

 much, perhaps, for the sake of the color it imparts by itself, as that it 

 serves as a mordant to fix colors on cotton and flax, which could not 

 otherwise be so well employed on these kinds of fibers. Grace Cal- 

 vert,^ for exarajDle, says of sumac that it is largely used in Yorkshire to 

 mordant the cotton warps of mixed goods. By means of it the cotton 

 takes the same colors as the woolen weft with vegetable dye-stufts and 

 with aniline colors. But it is particularly under the influence of weak 

 alkalies that the tannins combine with vegetable fibers, and that they 

 absorb oxygen, turn brown, and become fixed upon the cloth. As Cal- 

 vert lias said, on p. 311 of the work just cited, all the tannins are re- 

 markable for the avidity with which they absorb oxygen in presence of 

 alkalies, being converted into bodies of various colors, green, red, 

 brown, and black. 



I find, on investigation, that methods of dyeing depending on the 

 action of alkalies upon tannin have long been in familiar domestic use 

 in this country ; the bark of the maple, alder, chestnut, walnut, and 

 butternut, and doubtless of other trees, being used in diS'erent locali- 

 ties, as well as the husks of several kinds of nuts. For example, L. 

 Stanley, of Maine,^ directs : "To color brown, make a dye of common 

 alder bark. First dip the articles in this, then wring them out and dip 

 them into weak lye. This will make the color light or dark, according 

 to the strength of the alder dye. It is a fast color." In the American 

 Agriculturist for January, 18G9,two or three receipts for dyeing tan-color 

 are giv^eu. In general, the directions are to boil black-walnut hulls to 

 a strong liquor, into which either cotton or woolen yarn may h^ i)utand 

 boiled for ten minutes. The yarn is then taken out and dipped in a pail 

 of strong lime-water, and the operation repeated until the color suits ; 

 or, instead of the hulls, chestnut or walnut bark may be used, or extract 

 of hemlock bark. ^ According to Porcher, * " the inner bark of the short- 

 leaved pine (P. treda) will dye cotton goods a brown color without the aid 

 of copperas. After boiling in the solution, dip in strong lye." I have 

 heard of alder bark and soft soap being used in domestic dyeing m 

 Nova Scotia for coloring linen tan-color; and it is plain that the soap 

 would exert an alkaline action in this case, even if it served no other 

 purpose. It appears from all this that while tan liquor alone is un- 

 doubtedly used in some localities for staining canvas and twine, there are 



' "Dyeing aad Calico Priuting," Manchester, 1876, p. 320. 



2 American Agriculturist, February, 18G7, 26, 48. 



^American Agriculturist, November, 1868, p. 401. 



■* "Resources of the Soutbern Fields and Forests," p, 585; cf. pp. 215 and 217. 



