Note 10 — PART II.
Reading edition
Guernsey Blue.—The darkest of the Nicholson Fast Blues. On a bottom of barkwood, camwood, madder, or inferior indigo, produces an indigo blue which will stand all the acid tests the same as colors made from indigo.
Serge Blue.—It will be found very serviceable to give bloom to goods dyed with indigo, and by itself shows a very good indigo test with nitric acid.—Instructions for Working the Atlas Works Aniline Dyes.