SORGHUM DYE. 995 
vations respecting the mode of using this new dyeing ma- 
terial, derived from experiments conducted by himself in 
the laboratory at Washington City: 
* “The simplest solvent is alcohol (very expensive at 
present). Dilute acids were resorted to with very good 
success, and at an expense and trouble hardly worth men- 
tioning. The seeds were boiled in vinegar, or in water to 
which oil of vitriol had been added, before heating, until 
the mixture tasted as acid as vinegar. Other acids, such as 
tartaric, oxalic, etc., can be used, but are more expensive. 
When the liquid assumes a red or rather an intense orange 
color it is ready for use. The articles to be colored are at 
once brought into the hot solution, and agitated until the 
coior no longer increases. They are at once removed and 
dipped into a weak solution of salt of tin (chloride of tin), 
obtained by dissolving tin in hydrochloric acid. They are 
then exposed to the air for a short time, and washed. 
“Cotton and silk may thus be colored red, wool turns to 
a beautiful purple, and an almost unlimited variety of colors 
and shades may be obtained by substituting for salts of tin 
other mordants. All the various shades of red, purple, 
orange, gray, etc. are thus produced from the same bath, 
the cloths being afterward drawn through solutions of pro- 
tochloride of tin, bichromate of potash, sulphate of copper, 
ammonia, lime-water, subnitrate of bismuth, ete. Yellow is 
produced by adding to the seed sufficient nitric acid to form 
a thick mushy mass. Too much acid will make a straw 
color. 
“The dye turns solid by standing, and may thus be stored. 
To dye silk or wool yellow, the solid dye is dissolved in 
boiling water, the goods dipped into it and afterward 
washed. 
eS SL 
* Report of Department of Agriculture, 1864, p. 532. 
