Basic fuchsin is a mixture of some chemically related dyes. However, the proportion of each dye in the mixture varies. Due to this, samples of basic fuchsin may not be suitable for particular purposes. If using it for making Schiff's reagent, a batch which has a high proportion of pararosanilin is required, as it is this component that makes the best Schiff's reagent. Some companies specify selected batches as being suitable for making Schiff's reagent, or pararosanilin may be purchased by name. The other major component in the mixture is rosanilin. There may also be amounts of magenta II and new fuchsin. The proportions of these last two dyes is minor, and they may be absent.
R. D. Lillie.
Conn's Biological Stains
Williams & Wilkins, Baltimore, MD., U.S.A.