THE MICROSCOPE. pw ak 
Warm it first, to drive out all moisture.* Then pour in absolute 
alcohol till the tube is one-third full, and apply a gentle heat 
until it has a deep, blood-red color. Let it cool and settle; then 
pour off into a one or two-drachm vial, according to quantity in the 
tube, being careful not to get any of the undissolved dye into 
the vial, or you may filter it, incurring considerable waste. Then 
pour absolute alcohol into another vial till half full; then pour off 
the strong stain into the absolute alcohol until it has a medium red 
color when held to the light. Keep the vials tightly corked to avoid 
moisture, evaporation and dust. 
Proceed to stain as follows: 
First, immerse the section in the blue stain from two to ten 
hours until as blue as desired, when washed in clean water. Then 
dehydrate it thoroughly (alcohol cannot remove any of this stain or 
color), and float it on turpentine or essential oil. I think turpentine 
is just as good, and is much cheaper than the essential oils for 
general use. If the section is very frail, as sections of pig’s lung, 
float it on to a cover-glass or mica in the turpentine, and lift it onto 
a slide, the mica between the section and slide, and apply the red 
stain in small quantities to the section with a camel’s hair brush, 
keeping the specimen moist with turpentine, when the stain evapo- 
rates. Examine with the microscope as you proceed with the stain- 
ing. If you see the stain is too weak when applied freely, add 
some of the strong stain to it until of right color. If section is over- 
stained red, wash it out with absolute alcohol till the color is suffi- 
ciently removed. Then wash out any surplus of red stain or colored 
turpentine with fresh turpentine, and if there is any dirt to remove, 
taking some time to fish out, apply a drop or two of aniseed oil, which 
is the least volatile essential oil I know of. Then push the mica off 
the slide so as to grip it with the tweezers, and pull it away from the 
slide horizontally. Invert it and lay it on a clean slide, warmed, hav- 
ing plenty of balsam on it. Then hold the slide vertically and push 
the mica upwards off the slide so you can grip it with the tweezers 
and pull it off. If there is no objectionable dirt on it, lay a clean 
cover-glass on it and proceed as already described. The red stain 
can be made weaker by adding absolute alcohol to it, and stronger 
by adding the strong staining solution to it. 
If sections are overstained in the blue stain, let them soak in 
plenty of distilled-water, or clean, soft water, from five to fifteen 
hours. 
* The vials, etc., should be as clean as possible, free of fibres or dust, and warmed to 
drive out all moisture, before putting absolute alcohol into them. The smallest quantity 
of moisture affects the beauty of the work. 
+ The alcohol spurts out when heat is too high and tube too full. 
