160 G. C. KAROP ON A SPECIMEN OF BACILLUS TUBERCULOSUS. 



other hand, where there is great breaking down of the lung and 

 near the fatal termination of the disease, they are grouped in masses 

 and in great quantity ; but there are many exceptions to this, and 

 individual cases vary considerably. 



There seems to be no doubt that they increase most rapidly, and 

 are to be found most readily in the caseous matter lining the walls 

 of the cavities in the lung, so that the thick, and not the watery, 

 part of the sputum should be used for preparing specimens. 



Again as to the methods of staining the bacillus. In the above 

 communication Dr. Gibbes' procedure was advocated as the easiest 

 and simplest, and it is still, with some later improvements, the one 

 ordinarily used; but Dr. Neron (Lancet, Dec. 23, 1882) and some 

 others have shown that it does not differ in any essential way from 

 that of Ehrlich, which preceded it. A solution of methyl blue is 

 now used instead of chrysoidin for staining the surrounding matters, 

 as it affords a greater contrast to the magenta red ; no second stain 

 however is really necessary. Eecently Dr. Gibbes (Lancet, May 

 5th) has given a " Kapid Method of Demonstrating the Tubercle 

 Bacillus without the use of Nitric Acid," which it may be as well 

 to transcribe. " The stain is made as follows : — Take of rosanilin 

 hydrochloride two grammes, methyl blue one gramme ; rub them 

 up in a glass mortar. Then dissolve anilin oil 3 c.c. in rectified 

 spirit 15 c.c. ; add the spirit slowly to the stains until all is dis- 

 solved, then slowly add distilled water 15 c.c. ; keep in a stoppered 

 bottle. To use the stain : — The sputum having been dried on the 

 cover-glass in the usual manner, a few drops of the stain are poured 

 into a test tube and warmed ; as soon as the steam rises pour into 

 a watch-glass, and place the cover-glass on the stain. Allow it to 

 remain for four or five minutes, then wash in methylated spirit until 

 no more colour comes away ; drain thoroughly and dry, either in 

 the air or over a spirit lamp. Mount in Canada balsam." 



A certain degree of temperature is necessary for successful stain- 

 ing, and there is no doubt that many of the earlier experiments 

 failed from being made in too cold a room. All observers now 

 agree that a temperature of about 100° to 104° F. is almost abso- 

 lutely necessary as a condition of success. This may be attained by 

 either warming the stain first or keeping the covers while staining 

 in a warm chamber. 



