15ft THE MICROSCOPE. 



staining the spores will appear isolated and their relation to the 

 bacilli not easily recognized. 



See the A. M. M. J. Vol. XIII, Page 3, for an excellent arti- 

 cle by Dr V. A. Moore. 



170. — How can I stain sputum for the Pneumococcus, and material 

 from the brain for bacteria in meningitis ? — L. 



Make two fluids: an aniline-water-fuchsin as above, and sat- 

 urated solution of methyl-blue in water. Prepare cover glasses 

 by flatmng. Stain in the fuchsin about one minute, then im- 

 merse in the methyl-blue about three minutes. Wash in water, 

 dry and mount in xylol balsam. 



171. — Give the best method for staining anthrax bacilli in tissues, 

 diphtheria and typhoid bacteria in tissues and on covers. — L. 



Take Methyl blue, 2 parts; alcohol, 15 parts; water 85 parts ; 

 and mix well. The sections should remain in this stain for 24 

 hours, then be very carefully decolored in weak acetic acid. 



Too much bleaching will bleach the bacilli also. A certain 

 pale blue tint will indicate that the tissue is well bleached and 

 the bacilli practically untouched. Wash quickly in water, 

 dehydrate in absolute alcohol, clear in oil of origanum and 

 mount in xvlol balsam. 



PRACTICAL SUGGESTIONS. 



By L. A. WILLSON, CLEVELAND, OHIO. 



Cuticle of Equisitum. — The cuticle of the Scouring Rush 

 (equisitum) is a fine polarizing object. To mount, cut the stems 

 into suitable sizes. Place the pieces in a -test-tube half full of 

 water, add a few drops of nitric acid and boil for a few minutes 

 over a spirit lamp. The cuticle which is pure silex, separates 

 from the vegetable portion and rises to the surface. Next, wash 

 thorourghly so as to remove all traces of the acid. Then place the 

 pieces between two slides and hold them together with a spring 

 clip. Leave them in that position until they are dry and flat- 

 tened; then remove and mount in balsam. 



Crystals of Urine. — Urine is an exceedingly crystal - 

 izable substance and slides are very easily prepared for the 

 polarisco,)e. Let it settle in a conical glass from twelve to 

 twenty-four hours. Take a portion of the sediment in a pipette 

 and place it in the center of a slide. Cover the slide so as to 



