ONE HUNDRED THOUSAND FACTS FOR THE PEOPLE. 571 



is in compounding the dyeing materials, 

 and making a homogeneous liquor ot 

 them, so as to produce the desired shade, 

 after being saddened or made of a dark 

 color by means of green copperas, which 

 is generally used to darken brown grays, 

 blacks, slate colors, etc. Sumach and 

 fustic, or sumach alone, is the general 

 ground of browns , the red, as I have 

 before observed, is obtained by archil, 

 and the black hue by green copperas in 

 warm water; after the feather has been 

 put into the copperas-water, it may be 

 returned again into the dye-water, and 

 back again into the copperas ; but care 

 should be taken, each time, that the 

 feather is rinsed from the copperas-water 

 before it is again returned into the 

 dye - liquor, otherwise copperas would 

 spoil it. 



The same preparation as would dye silk 

 of the same color will dye feathers ; in 

 short, feathers as well as silk, being 

 animal substances, are more alike in 

 nature than any other two bodies, either 

 animal or vegetable. You must remem- 

 ber that in dyeing silks that the water is 

 used hot, or on the simmer, for most 

 colors; but feathers must always be 

 dyed in cold liquors, except for black, the 

 dyeing materials being first boiled, and 

 then left to cool; your feathers must 

 then be put in, and when this liquor is 

 exhausted, add a fresh one, pouring off 

 the old liquor. 



Mordants are earthly and metallic com- 

 pounds, the base of which unites both 

 with the fibres of the material to be 

 dyed and the coloring matter. In calico 

 printing the mordants are formed into a 

 paste, with some gum or other thickening 

 material, and printed with wooden blocks 

 on the cloth, which, after being dried, 

 &c, is passed through the liquid dyes. 

 The coloring matter combines with the 

 parts so printed, but is easily discharged 

 from the other parts. The principal 

 mordants are the following : 



Mordant, Alum, an alum, with one- 

 fourth its weight of tartar, acetate of 

 alumina. This is commonly prepared in 

 a solution for this purpose ; one hundred 

 and fifty parts of alum, in pyrolignite of 

 lime of twenty degrees density, is some- 

 times employed. 



b. A solution of alum with crystallized 



carbonate of soda, in the proportion of 

 one ounce to each pound of alum. 



c. This is a solution of alum with 

 sufficient strong solution of caustic potash 

 to re-dissolve the precipitated alumina, 

 to which mixture a portion of linseed oil 

 is added. 



d. To fifty gallons of boiling water 

 add one hundred pounds of alum; dis- 

 solve, and add slowly ten pounds of crys- 

 tallized carbonate of soda. When the 

 effervescence is over add seventy-five 

 pounds of sugar of lead. 



MORDANT, a Protochloride of Tin. 

 — a. To strong muriatic acid add grad- 

 ually small pieces of grain tin till no • 

 more is dissolved. It may be obtained 

 in crystals by evaporation. In dissolving 

 them, it is necessary to add to the water 

 a few drops of muriatic acid. 



b. Nitro-muriate, or perchloride of tin. 

 Mix one measure of nitric acid with four 

 of muriatic acid, and add tin in small 

 quantities as long as any is dissolved. Or 

 mix four ounces of muriatic with one of 

 nitric acid and one of water; dissolve in 

 it, by small portions at a time, two 

 drachms of grain tin. 



c. Aquafortis (or equal portions of 

 nitric acid and water) eight parts; sal 

 ammoniac, one part ; mix, and add grad- 

 ually one part, or as much as it will dis- 

 solve, of grain tin. 



d. Dr. Bancroft's murio-sulphate of 

 tin. Digest two parts of tin with three 

 of strong muriatic acid for an hour. Add 

 very cautiously one and one-half part of 

 oil of vitriol. Keep up the heat as long 

 as hydrogen is evolved ; on cooling, it 

 crystallizes. Dissolve this in salt and 

 water, so as to form a solution containing; 

 one part of tin in eight. 



e. New tin crystals. Add three pounds 

 of sal ammoniac to a gallon of solution 

 of tin ; evaporate and crystallize. 



/. Mordant for lac-dye. Mix twenty- 

 seven pounds of muriatic acid with 

 one and one-half pounds of nitric acid 

 (sp. gr. 1. 19.), put into a stone bottle, 

 and add in small bits, till four pounds are 

 dissolved. 



g. Stannate of soda. Digest litharge 

 thirty-six parts, or minium twenty-seven 

 parts, in a metallic vessel, with a soda 

 lye of one and thirty-five one hundredths 

 density; when dissolved, eight parts of 

 tin in grains are gradually added. The 



