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 gives 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 

 approximately 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 tog-ether 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 edg-e projecting, on the end 

 of a strip of metal about half-an-inch wide and eig-httoten 

 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. 



