THE MICROTOMIST'S VADE-MECUM

RIC(
CHAPTER VII.
ALCOHOLIC CARMINE (OXALIC, BORACIC, HYDROCHLORIC, ANA
SULPHURIC).
80. Oxalic-acid Carmine (Thiersch's formulal).-Make a       ibr 4p
solution of 1 part by weight of carmine in 1 of ammonia and  so
3 of water; to 1 volume of this add 8 volumes of an aqueous  cauan
solution of oxalic acid of 1: 22 strength; to this mixture add  Nquaho
12 volumes absolute alcohol, and filter.                    tiw ad
The filtrate may be made to assume at will an orange hue,  riWtiO
by the addition of oxalic acid, or a violet hue, by the addition  oibbI
of ammonia. Either may be used for staining. If the addi-
tion of oxalic acid cause a crystallisation of the acid oxalate  k(
of ammonia, this may be dissolved by means of a few drops    thh
of distilled water or ammonia; or it may be removed by         U{h
filtering.
If the* concentrated violet fluid be tak~en for staining,   d O
sections are stained in a few moments, uniformly, but cells   gv)
Tather more deeply than other tissue- elements. To stain 0ovis
slowly, the  solution must be diluted     with  alcohol of    tha TCR
70 to 80 per cent.; not with absolute alcohol, which would i thed
precipitate the acid oxalate of ammonia. Overstains may be     s
washed out in a few minutes in an alcoholic solution of
oxalic acid. The stain is equally applicable to alcohol-and   sasl
to chromic acid- preparation s.                               Aa
80a. Lilac Borax-carmine S in (Thiersu'sformula). -One llsli
part of carmine and 4      parts borax aredissolved in 56 parts   ir
'Arch. Mik. Anat.,' i (1865), p. 149.
2 Arch. Mik. Anat.,' i (1865), p. 150.

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