214 Tue Microscope. 
2d. Soak it in alcohol for ten minutes. 
3d. Remove it to water for one minute. . 
4th. Immerse it for two hours in Carmine fluid, made as 
follows :—Carmine, 15 grains; Ammonia, 15 grains; Water, 2oz. 
Dissolve the carmine in the ammonia by means of gentle heat, 
add the water, and filter. 
5th. Wash thoroughly in water. 
6th. Place in alechol for ten minutes. 
7th. Float upon oil of cloves and mount as previously 
described. : 
Mr. Gilbert, whose vegetable preparations are most suc- 
cessful, recommends the following double-staining fluid, in 
which the sections are immersed, and which produces perfect 
differentiation. Dissolve of Magenta Crystals 4+ grain in 1 
ounce of alcohol, and of Nicholson’s soluble blue one sixth 
grain in | ounce of alcohol; add to this 4 drops of nitric acid. 
Filter both solutions. 
To two parts of the blue add 7 parts of the magenta 
solution. Immerse the section for from 1 to 2 minutes, remove 
it to absolute alcohol, thence to Benzole (to fix the magenta) ; 
thence to oil of cloves, and mount in Balsam. 
Picro CARMINE, DousLe Srarintne.—Picro Carmine as a 
selective double stain cannot be surpassed. The process is as 
follows :—Take of carmine 2 grains, liquor ammonia 4 drachm, 
distijled water 1 ounce; dissolve the carmine in the ammonia 
by means of gentle heat, add the water. Dissolve 8 grains of 
picric acid in 1 ounce of alcohol, also by means of gentle heat, 
and mix the two solutions. 
Place the sections in alcohol for one hour—immerse them 
in the recently filtered staining solution for from half an hour 
to three hours—z. ¢., until they are sufficiently stained,—wash 
them in alcohol, immerse them in an alcoholic solution of 
Picrate of ammonia for one hour, and for a second hour in a 
like solution, in other words, change the solution once during 
the two hours. Place them inalcohol for a few minutes, and in 
oil of cloves as already described, and mount in Balsam.— 
From “ Cole's Studies” for June. 
*Insects removed trom Liq. Potass, 1fter being soaked in water for 24 hours, 
should be kept in strong, or glacial, acetic acid and glycerine (half and half) until 
required for mounting, 
