109. Yellow Spirits

109. Yellow Spirits are prepared in the same way, only substituting sulphuric acid for the nitric acid. This is used for the same purposes as red spirits, with the advantage of the economy of sulphuric over nitric acid.

110. Barwood Spirit

110.    Barwood Spirit is prepared by using 5 measures hydrochloric acid, 1 nitric acid and 1 water, dissolving in this 1 ounce feathered tin for every pound of the whole mixture. 11/2 ounces tin may be used if the red dye is required to be very deep.

111. Plumb Spirit

111.    Plumb Spirit is made by using 6 to 7 measures hydrochloric acid to 1 nitric acid and 1 water, dissolving in it 11/2 ounces tin for each pound of the acid mixture. This spirit is named from a preparation made with it and a decoction of logwood. A strong solution of logwood is made and allowed to cool, then to each gallon of the solution there is added from 1 to 11/2 pints of the spirit; the whole is well stirred and set aside to settle. This preparation has a beautiful violet color, and silk and cotton are dyed of that shade by dipping them into this plumb liquor without any previous mordant. The depth of tint will depend on the strength of the solution.

112. Plumb Spirit for Woolen Dyeing

112.    Plumb Spirit for Woolen Dyeing. This is prepared by adding tin to nitric acid in which a quantity of chloride of ammonium (sal ammoniac) has been dissolved. Observe, that all these spirit preparations are varied by different operators, some preferring more or less of the two acids, and also of the tin; but the proportions given form good working spirits, and if care be taken in their preparation not to fire them, that is, not, to allow the temperature to get so high as to convert the tin into a persalt, the operator will not fail in his processes as far as the quality of the spirit is concerned.

113. Tin Spirits

113.    Tin Spirits. The following are among the best recommended preparations of tin spirits, used for dyeing scarlet:

1 pound nitric acid, 1 pound water; dissolve in this 11/2 ounces sal ammoniac, and then add, by degrees, 2 ounces pure tin, beaten into ribbons.

Or: dissolve 1 part sal ammoniac in 8 parts nitric acid at 30° Baum'e; add, by degrees, 1 part pure tin; and dilute the solution with one-fourth its weight of water.

Or: 4 parts hydrochloric acid at 17° Baum'e, 1 part nitric acid at 30° Baum'e; dissolve in this mixture 1 part pure tin.

Or: 8 parts nitric acid, 1 part sal ammoniac or common salt, and 1 part grain tin. This is the common spirit used by dyers.

114. Alum Plumb

114.    Alum Plumb. Make a strong decoction of logwood, and then add to it 1 pound alum for every pound of logwood used.

115. To Test the Purity of Alum

115.    To Test the Purity of Alum. The usual impurity which renders alum unfit for the uses of the dyer, is the ferro-sulphate of potassa, but if iron be present in any other shape it is equally injurious. Common alum frequently contains ammonia, from urine or the crude sulphate of the gas works having been employed in its manufacture. This may be detected by adding a little quicklime or caustic potassa. Pure alum should form a colorless solution with water, and give a white precipitate with pure potassa soluble in an excess of the latter. It should suffer no change on the addition of tincture of galls, prussiate of potash, or sulphureted hydrogen.