1884.] 



MICKOSCOPICAL JOURNAL. 



197 



staining be carefully applied, and that 

 the microscope employed be of suf- 

 ficient power to bring the bacillus 

 distinctly into view. Among the 

 many methods and modifications of 

 methods that have been suggested, or 

 are in actual use, I select the one now 

 employed by the discoverer of the 

 bacillus himself. It is his original 

 method, considerably modified by 

 Ehrlich and Weigert. In the second 

 volume of the ' Mittheilungen aus 

 dem Kaiserlichen Gesundheitsamt,' 

 Berlin, 1884, he gives a very clear 

 and minute account of it, of which 

 the following is a brief summary : — 



Five c.c. of pure anilin (an oily, col- 

 orless liquid, later turning brown) is 

 shaken up repeatedly with 100 c.c. 

 of distilled water. In half an hour 

 about three to four per cent, of the 

 anilin is dissolved ; the rest of the oil 

 settles to the bottom. This mixture 

 is filtered through a moistened filter, 

 and the filtrate, if not absolutely clear, 

 must be filtered again. The solution, 

 or so-called anilin v\^ater, thus ob- 

 tained does not keep, but must be pre- 

 pared anew whenever it is to be used. 



To 100-150 'C.c. of absoluted al- 

 cohol,* in a well stoppered bottle, 

 about 30 grammes of dry methyl- 

 violet is added and the whole allowed 

 to stand for several days. Repeated 

 shaking, in the meantime, will aid 

 the solution, which ought to be a sat- 

 urated one. At the end of this time 

 some of the methyl-violet should, 

 therefore, remain undissolved in the 

 bottom of the bottle, "which may be 

 utilized later on by the further addi- 

 tion of alcohol. Fuchsin, when used 

 in place of methyl-violet, is treated 

 in the same way. It is said to be 

 better adapted for permanent prepa- 

 rations. 



Eleven c.c. of the alcoholic solution 

 of methyl-violet is now mixed with 

 100 c.c. of the anilin water, and the 

 staining fluid is ready for use. Koch 

 advises the further addition of 10 c.c. 

 of absolute alcohol, which will pre- 



* 95 per cent, alcohol will probably suffice whenever 

 absolute alcohol is spoken of. 



serve the fluid for about ten days 

 without necessitating filtering each 

 time it is used. 



The sputum should be as free as 

 possible from intermixture with the 

 secretions of the pharynx, mouth, etc. 

 The expectoration should not be a 

 forced one, the irritation producing 

 the cough being spontaneous and 

 natural. In the foamy mucus will 

 be found small, tough, yellowish 

 lumps, sometimes few in number and 

 sometimes making up the entire bulk 

 of the expectorated mass. A small 

 portion of such a yellow mass only 

 should be chosen. Drawing it to the 

 edge of the glass and up the sides, it 

 may there be broken up into still 

 finer proportions with a scalpel, and 

 spread out in a very thin layer upon 

 a chemically clean cover-glass (after 

 soaking in nitric acid and washing in 

 alcohol) and allo'wed to dry com- 

 pletely. Some suggest that two cov- 

 er-glasses be rubbed together with the 

 sputum between them, which will 

 then become very thinly and evenly 

 distributed upon both cover-glasses. 



When dry, the cover-glass is drawn 

 through the flame of a Bunsen burner 

 (or alcohol lamp) three times with 

 moderate rapidity, the side covered 

 with the sputum being held upwards, 

 so that the flame cannot touch it di- 

 rectly. Or it may be placed in a dry 

 chamber at iio^ C. for twenty min- 

 utes. This procedure causes firm 

 adhesion of the layer to the cover- 

 glass even w^hile undergoing the ma- 

 nipulations to be shortly described. 



Staining. — The preparation is 

 stained by gently placing the cover- 

 glass, with the dried layer dii'ected 

 downwards, upon the surface of the 

 staining fluid in a watch-glass, where 

 it will remain floating. At the end 

 of several hours it is removed. The 

 process may be hastened by heating 

 the staining fluid with the floating 

 cover-glass over a lamp until bubbles 

 appear. It is then removed, and 

 after waiting ten minutes longer the 

 staining is completed. The former 

 method is preferable. 



