80 Tue Microscope. 
FOR STAINING BACILLUS TUBERCULOSUS WITH DR. GIBBES’ DOUBLE 
STAIN. 
Pour a little Stain into a test tube and warm; as soon as it 
begins to steam, pour into a watch-glass and invert the cover- 
glass with the Sputum on the Stain; allow it to remain for five 
minutes, then wash in Methylated Spirit until no more color 
comes away; dry and mount in Balsam solution. 
FOR STAINING ALL OTHER BACTERIA. 
For Fluids, such as Urine, Pus, Sputum, ete., containing 
Bacteria, spread a small portion of the fluid on one surface of a 
cover-glass, and dry in air. Warm over a spirit lamp to make 
it adhere. Float the cover-glass, object downward, on small 
quantity of the New Purple Stain. Hold the watch-glass over 
a spirit lamp for a few seconds until the Stain becomes warm, 
leave for five minutes. Then wash in Spirits, dry, and mount 
in Balsam solution. 
If the Stain be used cold, the cover-glass must be left in for 
half an hour. 
——S10 > —_ 
STUDIES IN HISTOLOGY. 
LESSON II. 
BY C. H. STOWELL. 
HARDENING, SOFTENING, DISSOCIATING:-AND NORMAL FLUIDS. 
EARLY all of the animal tissues require hardening; a few 
N require softening; while others have to be examined in some 
normal fluid medium. 
The tissues should be as fresh as possible and should be cut 
at once into small pieces. The size of the pieces will depend 
upon the penetrating power of the hardening fluid, ‘“ Miiller’s 
fluid” being remarkable in this respect. 
Portions of such solid organs as the liver and kidney need 
not be cut into pieces smaller than an inch square, while por- 
tions of such tissues as the stomach, cesophagus, intestine, and 
spinal cord need not be cut only sufficient to handle them con- 
veniently, if Miiller’s fluid be used. 
