84 METHODS OF MICROSCOPICAL EESEAECH. 



rendered more brilliant, and any diffuseness re- 

 moved by immersion in 



Hydrochloric Acid, 1 per cent, in Distilled Water, 1 part. 

 Alcohol (Rectif.), 2 parts. 



PICEO-CAEMINE STAINING FLUIDS. (Gage's Formula.) 



1. Take of carmine and of picric acid equal 

 parts by weight. Dissolve the picric acid in 100 

 times its weight of distilled water. Heat may be 

 used if necessary. Dissolve the carmine in 50 

 times its weight of liquor ammonia fort., B.P. 



Mix the two solutions, filter through thick filter- 

 paper, evaporate the filtered liquid to dryness, 

 dissolve the filtrate in 100 times its weight of 

 distilled water. Filter until a perfectly clear solu- 

 tion results. Then add to each 100 c.c. of the 

 solution, 



25 c.c. of Glycerine (Price's). 

 10 c.c. of Absolute Alcohol. 



This will keep perfectly well, but should be 

 filtered at intervals of a few months. 



2. WEIGEET'S FOEMULA. 



Soak 2 grammes of carmine for twenty-four 

 hours in 4 grammes of ammonia. Place it under 

 a glass shade to prevent evaporation, add 200 

 grammes of a very strong solution of picric acid, 

 and replace it under the glass shade for a second 

 period of twenty-four hours. Then add, very 

 gradually, acetic acid until precipitation com- 

 mences. Again put it aside for twenty-four hours. 

 Filter, then add ammonia in small quantities drop 

 by drop at intervals of twenty-four hours until the 



