THE Microscope. 79 
repeatedly as long as color comes freely. Allow to settle, place 
a drop on cover, when dry enough to adhere, rinse off with 
alcohol to get rid of water, dry. Wet with spirits of turpentine 
and mount as usual in Balsam. 
I have followed green on the red with good results, foreign 
matter will dye bright green before the red leaves the casts. 
In using green alone, I find the casts and epithelium stain 
a purplish blue, while much foreign matter (dust) will be a bright 
green. In this case color will distinguish a cast if form does 
not. Hope some of your readers will make a trial. 
—____—_—<¢e 
BACILLUS STAINING. 
Cc. H. STOWELL. 
E copy the following from a circular issued by W. H. 
Walmsley & Co., giving a list of their staining reagents: 
FOR STAINING AND PREPARING SPUTUM FOR DETECTION OF BACILLUS 
TUBERCULOSUS. 
Obtain fresh sputum—coughed up in the morning. Spread 
a small portion upon one surface of a thin cover glass and dry 
in the air. Pour a few drops of the Magenta stain into a watch- 
glass. Hold the watch-glass over a spirit lamp for a few seconds 
until the stain becomes warm, and place the cover glass, sputum 
downward, upon its surface—leave it in for five to ten minutes 
—then wash it in dilute Nitric acid (1 to 3) until all color per- 
ceptible to the eye has disappeared. Wash in distilled water 
to remove all traces of acid. Then float the glass, sputum 
downward, for two or three minutes upon afew drops of Methyl 
Blue stain—again wash in distilled water—then immerse in, 
absolute alcohol for a few minutes to remove all trace of water. 
Dry thoroughly in the air. 
If the Magenta Stain be used cold the cover-glass must be 
left in it for half an hour. 
When dry, place a drop of Balsam solution on the cover- 
glass and lay it carefully on a glass slide. If wanted for exam- 
ination at once or with oil immersion, run Hollis’ glue round 
the edges of the cover. 
