MULTIPLE STAINS

z secretions to the taste-organs stain a totally different colour.
I In an examination I lately made in a case of dysidrosis," he
continues, " I was able to stain the duct of the sweat gland
an entirely different colour from the surrounding tissues, and
so demonstrate its relation to the vesicles."
182. Picro-Carmine and Eosin (Lang's formula ').-Take
50 parts 1 per cent. picro-carmine, 50 parts 2 per cent. eosin
(aqueous solution). The objects, previously hardened in
alcohol, are left in the mixture half to four days.  Wash out
t the picrin by 70 per cent. alcohol, which must be frequently
L changed, and be followed by 90 per cent. and absolute
alcohol until no more eosin is dissolved out.
A nuclear stain. It is a double stain. The function of the
eosin appears to be that by reason of its superior penetra-
t tion it serves as a vehicle to carry the picro-carmine through
I tissues which would otherwise be impermeable to that sub-
stance.
For Turbellaria.
1 ' Jonrn. Roy. Mic. Soc.,' ii, 163. ' Zool. Anz.,' ii, p. 45. ' Mitth. d.
Zool. Stat. zu Neapel,' Bd. ii, p. 1, et seq.

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