1900] MICROSCOPICAL JOURNAL. 57 



blue, gentian violet, or Bismarck brown is obtained by pow- 

 dering- one "Soloid" stain in 7 c.c. (two drachms) of distill- 

 ed water, and then well shaking-. Five to ten per cent dil- 

 utions with distilled water of these saturated solutions are 

 well adapted for ordinary staining- purposes. Thus one 

 drachm of saturated solution made up to two ounces with 

 distilled water g-ives 1 in 17, or a 6 per cent solution. A 

 saturated alcoholic solution of methylene blue, g-entian vio- 

 let, or Bismarck brown may be obtained by heating- in the 

 same way one "Soloid" stain with a similar quantity of ab- 

 solute alcohol instead of distilled water. A saturated alco- 

 hol solution of fuchsine is obtained by heating- two "So- 

 loids" with 3"5 c. c. (one drachm) of absolute alcohol. A 

 solution of eosin suitable for general staining- is obtained 

 by dissolving one "Soloid" in 12*25 c. c. (three drahms) of 

 50 per cent absolute alcohol in distilled water. This gives 

 approximatel}^ a 0*5 per cent solution. Loffler's alkaline 

 methylene blue, aniline gentain violet, etc., can be readily 

 made as wanted in the same simple and systematic way. 



To Stain the Tubercle Bacillus. — Transfer a small quan- 

 tity of sputum, containing, if possible, one or more of the 

 small yellowish masses, to a glass slide ; cover this with a 

 second slide and rub the two together until the sputum is 

 thoroughly broken up and mixed. Draw one side of a clean 

 cover slip across one of the slides so as to cause a thin film 

 to adhere to it ; allow it to dry in the air, and fix by pass- 

 ing, with the film upwards, three times through the flame 

 of a spirit lamp or Bunsen burner. Now place the cover 

 slip film upwards, and with an edge projecting, on the end 

 of a strip of metal about half-an-inch wide and eight to ten 

 inches long, and carefully drop the carbol fuchsine solution 

 upon the film so as to cover it without running over on to 

 the metal. Place the metal in the flame at such a distance 

 from the cover slip that the stain just steams gently ; care- 

 fully avoid boiling, and after two minutes remove the slip 

 with forceps. Drain off the surplus stain on to blotting 

 paper, wash well under a tap or in a large beaker of water 

 and place for 10 seconds in 25 per cent hydrochloric acid. 



