1899] MICROSCOPICAL JOURNAL. 225 



ployed as the counter-stain. In this way four slides are 

 prepared by slightly different methods, whose results 

 should coincide. Where lithium carmine is employed as a 

 counter-stain the bacteria are shown as a deep violet on a 

 bright carmine background. As the bacteria are very 

 minute, and at times scarce, it may be necessary to search 

 a number of fields. Owing - to the affinity of the septum 

 between the diplococci for anilin stains, some of them sim- 

 ulate baccilli. Around a few of them the gelatinous cap- 

 sule may be seen faintly. The heavily stained elliptical 

 bodies are cells, repeatedly observed within the trachoma 

 nodule, which resemble myelocytes. 



Emulsions and Emulsifiers. — Each emulsion is exam- 

 ined under the microscope four times, the first time within 

 twenty-four hours after making,the second time after four 

 days, the third time after twelve days, and the fourth time 

 after thirty days, the object of the repeated examinations 

 being to ascertain if any changes took place in the size of 

 the oil globules on standing. Changes do take place if the 

 emulsion becomes rancid, but otherwise there is practi- 

 cally no change, as will be observed later. Decomposition 

 or spoiling of the emulsions must be avoided during the 

 period of the examinations, for otherwise the results will 

 be untrustworthy. Spoiling or decomposition cao be pre- 

 vented, where its occurrence is thought possible, by the 

 addition of a few drops of formaldehyde solution. 



In making certain microscopical examinations, a drop of 

 water was placed on the slide, the bottle of emulsion was 

 well shaken, a glass rod was dipped deep into the mixture, 

 and the end of this rod was then touched to the water on 

 the slide. The water diluted the emulsion so that measure- 

 ment of the globules was quite easy. The agitation of 

 the liquid was thought necessary to insure proper com- 

 minglingof the globules. The use of the glass rod avoided 

 touching the cork to the slide, which was found likelv to 

 have at its end some hardened, partially decomposed emul- 

 sion. Each specimen was given a number, and the results 

 of the examination are given in the Bulletin or Pharmacy 

 for June. 



