from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of a class of dyes, varying from blue to black, used in the manufacture of inks and for dyeing wood and textiles.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A dark blue synthetic dyestuff of the induline group.
from the GNU version of the Collaborative International Dictionary of English
- n. A dark blue dyestuff, of the induline group; -- called also azodiphenyl blue.
from The Century Dictionary and Cyclopedia
- n. A coal-tar color used in dyeing, prepared from the hydrochlorid of violaniline.
- n. The name is applied to three different coal-tar colors:
- n. Spirit-soluble nigrosine, which is closely allied to spirit-soluble induliue.
- n. Water-soluble nigrosine, which is the sodium salt of certain snlphonic acids of spirit-soluble nigrosine.
- n. Methylene gray (which see, under gray).
Experimentations in 1878 with the insoluble aniline blacks and vanadium were unsuccessful; but the soluble aniline black (blue-black) known as nigrosine they used and still use in various combinations.
Such inks are made from a fine, cheap powder, of which nigrosine is used in making black inks, eosine for red, and methylene for blue ink, and they cost only a few dimes a gallon to manufacture.