300 PATHOGENIC BACTERIA. 



organisms upon which he tried it. He deems it posi- 

 tively differential for the separation of the tubercle 

 bacillus and the smegma bacillus, as it does not color the 

 latter. 



It is said that the staining can be accomplished with 

 Merck's Soudan III., but not with Griibler's. Inmost 

 hands the method has not been a success. 



The possible relation that the number of bacilli in the 

 expectoration of consumptives might bear to the progress 

 or treatment of the case has been elaborately investigated 

 by Nuttall. 1 The total quantity of sputum expectorated 

 in twenty-four hours was caught in covered, scrupulously 

 clean conical glasses and measured therein. The pro- 

 portion of muco-purulent to fluid matter was noted. 

 Depending upon the degree of viscidity and number of 

 bacilli present in the sputum, a varying amount of 5 per 

 cent, caustic potash solution was added to it (from one- 

 sixth to an equal volume), and after the caustic potash 

 had rendered the sputum perfectly fluid more or less water 

 was added to dilute the mixture. The sputum, having 

 been measured, was poured into a perfectly clean wide- 

 mouthed bottle containing fine sterilized gravel or broken 

 glass. Rinsings of a measured amount of the caustic pot- 

 ash solution were used to free the conical glass from what 

 matter might remain and were added to the sputum. 

 The contents of the bottle were agitated in a shaking 

 machine for five minutes, and allowed to stand until the 

 caustic potash solution had had time to act. As soon as 

 the sputum had become homogeneous an equal volume 

 of water was added, and the whole shaken again. The 

 sputum thus treated was of a pale-green or yellowish- 

 brown color, and contained only small fragments of elas- 

 tic tissue. It was allowed to stand two to four hours, 

 and then shaken again for five to ten minutes. 



By means of a burette of original design drops of ex- 

 actly equal ' size were secured and caught upon clean 

 sterile cover-glasses. The drops were subsequently 



1 Bull, of the Johns Hopkins Hospital, May and June, 1891, ii., 13. 



