298 MICROSCOPICAL TECHNIQUE. 



First make a solution of i gm. of fuchsin in loo ccm. of a 

 5 per cent, aqueous solution of crystallised carbolic acid, adding 

 lo ccm. of absolute alcohol thereto. Of this add 15 drops, drop 

 by drop, to 20 ccm. of distilled water. To this add 8 drops of a 

 concentrated (saturated) solution of methylene blue and shake 

 well. 



The preparation, smeared on a cover-glass and dried, is floated 

 on this liquid for a few seconds, not less than eight or more than 

 ten, and is then rinsed with plenty of water. It is now ready for 

 examination under the microscope, in either water or glycerine. 

 All of the protoplasm, mucus, and necrotic cell elements, etc., will 

 appear stained a light red, while the fermentive organisms will 

 appear a deep blue and sharply defined, and the cell nuclei a 

 light blue, frequently tinged with red. 



Preparations made in this manner, afterwards cleared and 

 mounted in balsam or dammar, if kept in the dark, will preserve 

 their colour for a very long time, but soon fade if exposed to the 

 light. The stain should be kept not longer than a week, as it 

 begins to disintegrate after the expiration of eight or ten days. 

 The two solutions kept apart,^ however, remain indefinitely 

 unchanged. This process we have found to be especially adapted 

 to the detection and demonstration of Gonococcus Neiser.- National 

 Druggist. 



New Stain for Differentiating- the Bacterium Coli and Eberth's 

 Bacillus.— Ram ond''' has produced a stain with " rubine acid," 

 which stains the bacterium coli red very rapidly, while it does not 

 colour typhoid colonies. It is prepared by colouring a tube of 

 lactosed gelatin or gelose at four per cent., with a few grains of 

 " rubine acid.'' It is then decolourised by adding, while warm, 

 two drops of saturated solution of carbonate of soda. It is then 

 filtered and sterilised. It replaces Eisner's gelatin advantageously, 

 and owing to its extreme alkalinisation is not favourable to the 

 growth of other kinds of microbes. — -/our?i. Amer. Med. Assoc?i. 



* Bulletin Med., Nov. iiih, 1896. 



