110          THE MICROTOMIST 'S VADE-MECUM
phenylmethan; analogous in constitution to malachite     l
green).
Ponceau (which is the sodium salt of the acid compound   i3lt
dinitroxylolsulphate of naphthol).                      13 ,
Orange (which is the sodium salt of the acid compound     vi af
dinitrobenzolsulphate of diphenylamine).                Ie
Eosin. Fuchsin. Bismarck brown.                           &o
Most of these colours were obtained from     the manu-    iEl i
factory of Bindschedler u. Busch, Basel.
Eosin and ponceau were found to be useless, as they          5 010
cannot be made to afford a nuclear stain. Orange stains       sprad
precisely, but too weakly. All the others give good results.   &'il
Mauviin and rouge fluorescent often stain some nuclei much     0 (00'P
more deeply than others in the same preparation. Solid
green gives a weaker stain than safranin and magdala. It
is specific as regards the " Kerngertist " and nucleoli. Fuch-
sin gives a weaker stain than magdala, safranin, dahlia,
and mauvain. Bismarck brown was not very satisfactory
with chromic acid preparations; but with fresh alcohol
preparations gave a good, though not quite pure, nuclear
stain.  The best results were in     general obtained with
safranin, magdala, and dahlia.
The chief modification of Hermann's method insisted on by
Flemming is, prolonged staining in strong solutions.
Flemming sums up as follows the advantages of this
process :-" Whenever it is desired to preserve in their true
aspects the structure of nuclei, and the figures of nuclear
division, as they are preserved by means of chromic acid pre-
eminently; and further, to make such structures and figures a
susceptible of minute study by means of strong and accurate b
staining, in all such cases this method deserves preference over
all others.  Where, however, no more is desired than a          as
general nuclear stain without regard to minute faithfulness
of fixation, other known methods are more convenient,
especially alcohol-alum-carmine."
4IN       ?M                              o