Lofton-Merritt stain
A test used to determine the presence of
unbleached sulfate or sulfite fiber in paper. The
stain consists of two grams of malachite green in
100 ml. of water, plus one gram of basic fuchsin
in 100 ml. of water, 50 ml. of the former being
mixed with 100 ml. of the latter. The specimen is
treated with a drop of the mixture and then with a
0.1% solution of hydrochloric acid, followed by
the application of distilled water. A blue or
blue-green stain indicates the presence of
unbleached sulfate fiber, while purple or lavender
indicates unbleached sulfite. (143 )
![[CoOL]](/icons/sm_cool.gif){kind=icon}