Tue Microscope. 9 
der cochineal) until it is a vivid red, and then immediately re- 
moved to pure 70 and afterwards 90 per cent. alcohol. If thought 
desirable for delicate specimens which would suffer if placed in 
a weaker alcohol, the above solution may be changed by using 
50 or 60 per cent alcohol and dissolving both the borax and car- 
mine in that. The addition of a slight amount of glycerine, 
about 20 per cent., is sometimes very beneficial. 
BERMANN’S CARMINE. 
Take 5 grms. of carmine and dissolve in 8 grms. of ammonia, 
dilute this to 100 c. c. and add an equal volume each of absolute 
alcohol and glycerine. This fluid improves with time and may 
be used repeatedly. 
The after treatment is the same as recommended with bor- 
ax-carmine. The effect of the glycerine is to increase the inten- 
sity of the staining. 
The above two media cannot be too highly recommended. 
BEALE’S FLUID. 
Beemer tey ee 2226 3 2S eee 10 grains. 
ASTD DSS 2 eee 3 dr. 
0 OO pas ee 2 0z 
0 ao 2 02. 
RRs Sp ee 3 to 1 oz. 
The carmine is dissolved in the ammonia and the other 
components added. It is best to allow the mixture to stand 
open for a few hours to allow a possible excess of ammonia to 
evaporate. This fluid may be used for staining in toto if so de- 
sired, though for this purpose either of the above two fluids are 
better. In all cases the specimens are improved by the use of 
acid alcohol. 
ALUM-CARMINE. 
An aqueous solution of alum (1-5 per cent.) is boiled with 
an excess of carmine (4 or 1 percent.), allowed to cool and then 
filtered. A few drops of carbolic acid or a crystal of thymol 
~ should be added to prevent the growth of fungi. This colors 
_ quickly, though for objects in toto they may be left in the solu- 
tion for 24 hours. The above stains the nuclei more strongly 
than the other portions, but this effect is made more emphatic if 
the tissue is treated with acid-alcohol. 
If before staining the specimens be first placed in aezd gly- 
