METHYL-GREEN                        119
140. Methyl-Green (Calberla's observations ').-Calberla first
obtained this substance in 1874 from the " Chemische Fabrik"
of M. B. Vogel in Leipzig. It then went by the name of
"Vert en cristaux."
He then found that " the nuclei of subcutaneous connective
tissue and those of vessels and nerve-sheaths stained rose red,
cells of the corium reddish white, and the cells of epidermis
greenish blue to pure blue." Observations made in 1876 with
fresh samples of methyl-green, gave in the main the same
results, but the effects were not invariably produced and the
stain was not always stable.
141. Methyl-Green (Griesbach's method2).-Methyl-green is
not a derivate of rosanilin, but is obtained by treating methyl-
violet with methyl-nitrate (instead of methyliodide, as in the
manufacture of iodine-green).
Griesbach employs it in the same way as iodine-green; it
gives tolerable preparations, but these cannot be compared to
those obtained by means of iodine-green, and are less resistant
to alcohol.
Viallanes employs this reagent for the study of the histo-
logy (principally nervous) of insect larve. The tissues are
treated with 1 per cent. solution of acetic acid, and stained
(on the slide) in an aqueous solution of methyl-green ('Re-
cherches sur 1'histologie des Insectes, etc.,' These, Paris,
1883.)
142. Methyl-Green (Carnoy's methods ).-Methyl-green has
been largely employed by Carnoy for the study of nuclei in
the fresh state. He finds that it is a pure nuclear stain. He
states that it has the further advantage of being an admirable
fixing agent for nuclei. Cells die in it instantaneously, and
all permanent," vide' Quart. Journ. Mic. Sci.,' 1883 (N.S.), No. xc (p.
300).
'Morph. Jabrb.,' iii (1877), 3 Hft., p. 625.
'Zool. Anz.,' 117 (1882), p. 410.
3 Carnoy, ' La Biologie Cellulaire,' pp. 92, 144.

IIIMIII,