516 SUMMARY OF CURRENT RESEARCHES RELATING TO 



to the hardening of the sections ; Miiller's fluid must always be used, and 

 the tissues cut into very small pieces. 



For the first method the materials required are (1) a strong watery 

 solution of methyl-blue or Weigert's anilin oil solution, (2) a saturated 

 alcoholic solution of eosin, (3) a pipette, (4) absolute alcohol kept as free 

 as possible from water, (5) benzine and clove-oil in equal parts, with an 

 addition of absolute alcohol, sufficient to dissolve the turbidity which ap- 

 pears on shaking these reagents together, (6) fresh and neurly colourless 

 oil of cloves, (7) benzine, xylol, or cedar-oil. The sections, on being taken 

 from spirit, are placed in the methyl-blue solution, and eosin is immedi- 

 ately dropped in from the pipette — about equal parts should be used. The 

 sections should be at once removed to absolute alcohol, and, after a few 

 seconds' shaking, placed in the benzine and clove-oil mixture ; as soon as 

 the effects of the eosin begin to be apparent, they should be placed in 

 benzine and mounted. The whole process does not take more than a 

 minute. Sections thus stained show the bacteria and the nuclei blue, the 

 eosin stains the red blood-corpuscles orange, and the background of the 

 tissue is of a rose-red tint. 



Successful results were also obtained with watery solutions of Spiller's 

 purple ; as soon as the sections are placed in it an equal bulk of alcoholic 

 Spiller's purple must be dropped in from a pipette ; the sections are then 

 dehydi'ated in absolute alcohol as quickly as possible, and removed to the 

 benzine and clove-oil mixture. When cleared, the sections are placed in 

 eosin dissolved in oil of cloves, which stains the background red, and turns 

 out the excess of Spiller's purple ; the sections are then washed in oil of 

 cloves, passed through the benzine and clove-oil mixture, placed in benzine 

 and mounted. A somewhat similar method was adopted with fuchsin or 

 gentian-violet as the staining reagent. 



In all these methods, advantage is taken of the well-known fact that 

 benzine does not dissolve, and therefore fixes the anilin dyes ; one of the 

 advantages of placing sections in benzine before mounting is that any 

 residue of clove-oil is removed. Some of the methods used give results 

 which promise to be very permanent. 



Staining Cover-glass Preparations of Tubercle Bacilli.* — Dr. H. L. 

 Tohnan obtains very satisfactory results by the following modification of 

 the Weigert-Ehrlich method. 



(1) Anilin oil 30 drops, distilled water 3 oz. Shake vigorously for five 

 minutes and filter. 



(2) Saturated solution of fuchsin in 93 per cent, alcohol. Mix together 

 in a watch-glass 2 dr. of No. i. and 15 drops of No. 2. Upon this drop the 

 cover-glass, whereon the sputum has been applied in the usual manner, and 

 allow to stain for twelve hours. Decolorize in 33 per cent, nitric acid 

 until the colour has almost gone. By the use of heat the staining may be 

 effected in from 30-60 minutes ; but in this case the acid solution is not 

 stronger than from 5 to 15 per cent. 



The author recommends the following for preserving, and at the same 

 time staining sputum. The patient puts the sputum first coughed up in the 

 morning into a mixture of anilin oil solution, as above, 2 dr. ; fuchsin stain 

 20 drops, carbolic acid 10 per cent, solution 5 drops. 



This mixture is to be prepared fresh, and the sputum left therein for 

 at least twenty-four hours. 



This method, as far as time goes, is not to be compared to the Neelsen- 



* The Microscope, vii. (1887) pp. 83-4, from ' Medical Eeconl.' 



