and Laboratory Methods. 1769 



NORMAL AND PATHOLOGICAL HISTOLOGY. 



JOSEPH H. PRATT, Harvard University Medical School. 



Books for Review and Separates of Papers on these Subjects should be Sent to Joseph H. Pratt, 

 Harvard University Medical School, Boston, Mass. 



Leishraan. Note on a Simple Method of Pro- Since Jenner simplified the method for 



ducing Romanowsky Staining in Malarial ^he differential Staining of blood films 

 and Other Blood Films. Brit. Med. J., 2 : ° 



Sept. 21, 1901. two Other workers in this field have 



Wright. A Rapid Method for the Differential ~^„„ f.,^«-v,«^.. ,.^a u„, ^ ;^ j 



staining of Blood Films and Malarial Para- ^^"^ ^"^^^^"^ ^^^ ^^^^ improved upon 

 sites. J. of Med. Research, 2: 13S-144, his work in that their stains "sharply 

 '9°^- differentiate the nuclei and the cyto- 



plasm of the lymphocyte as well as the granulations of the leucocytes in general." 

 Leishman (Brit. Med. J., Sept. 21, 1901) prepares his staining fluid as fol- 

 lows : A one per cent, methylen blue (Griibler) solution is made in distilled 

 water, and then rendered alkaline by the addition of 0.5 per cent, of sodium car- 

 bonate. This solution is then heated to 65° C. in a paraffin oven, for twelve 

 hours, and afterwards allowed to stand at room temperature for ten days before 

 use. A 1 in 1000 eosin, extra B. A. (Griibler) solution is next made in distilled 

 water. The eosin and alkaline methylene blue solutions are now mixed, in equal 

 proportions, in a large open vessel and allowed to stand for from six to twelve 

 hours, being stirred from time to time with a glass rod. An abundant flocculent 

 precipitate results, which is collected on a filter and washed thoroughly with dis- 

 tilled water until the washings are colorless or have only a pale blue tinge. The 

 insolu"ble residue is carefully collected, dried and powdered. It has a greenish 

 metallic lustre. This powder is dissolved in the proportion of 0.15 per cent, in 

 pure methyl alcohol (Merck's for analysis being the best) and the resulting 

 solution is the staining fluid. It keeps well. 



To stain by this method the blood films are made in the usual way and 

 allowed to dry in the air. Three or four drops of the stain are then allowed to 

 fall on the slide, the forceps being used to gently rotate the slide so as to ensure 

 the stain being evenly distributed over the whole surface of the glass. No at- 

 tempt should be make to check evaporation. After about a minute double the 

 quantity of distilled water — that is, 6-8 drops — is added and allowed to mix with 

 the stain. Intimate mixture is hastened by rotating with the forceps as above. 

 The film is now allowed to stain for five minutes. Thick blood films or smears 

 from cellular structures, however, may require ten minutes. The stain is next 

 gently washed off with distilled water and a few drops of distilled w^ater are 

 allowed to rest on the film for one minute. This intensifies the Romanowsky 

 staining, removes the remains of the deposit and alters the tint of the red blood 

 corpuscles from a greenish blue to a transparent pink. The specimen is now 

 ready for examination and may be looked at in water or mounted in Canada 

 balsam. If distilled water be not on hand, rain or soft tap water may be em- 

 ployed instead. The whole operation of staining should not take more than 7-8 

 minutes from the time the blood is withdrawn. 



