854 PATHOGENIC MICROORGANISMS 



Add to this: 



Giemsa 's solution (fur EomanowsTci Farbung) 10-12 gtt. 



This staining fluid is left on for one to four hours, preferably in a moist 

 chamber. Wash in running water. Blot. 



By this method Spirochaeta pallida is stained characteristically 

 with a violet or reddish tinge. 



A rapid and convenient method for staining such smears consists 

 in the use of azur I and eosin in aqueous solutions as recommended 

 by Wood. The smears are fixed in methyl alcohol as before and 

 are then flooded with the azur I solution. The eosin solution is then 

 dropped on the preparation until an iridescent pellicle begins 

 to form. Satisfactory preparations may be obtained by this method 

 after ten or fifteen minutes of staining. 



A fairly satisfactory method of staining the treponema pallidum in 

 smear-preparations is that of Fontana. 22 For this method, the fol- 

 lowing solutions are necessary : 



1. Acetic acid 1 c.c. 



Formalin 2 c.c. 



Distilled water 100 c.c. 



Leave in one minute; wash in water. 



2. Phenol 86 per cent (liquefied crystals) 1 c.c. 



Tannic acid ... * 5 grams 



Distilled water 83 c.c. 



Cover preparation with this and steam gently one-half minute; wash. 



3. Silver nitrate 0.25 gram 



Distilled water 100 c.c. 



Ammonia q. s. 



Add ammonia drop by drop until the precipitate which first appears goes 

 into solution. Steam one-half minute; wash. 



Recently a rapid and extremely simple but not very reliable 

 method for the demonstration of Spirochaeta pallida in smears, by 

 the use of India ink, has been described. 



Smears are prepared in the following way: A drop of the fluid 

 squeezed out of the syphilitic lesion, as free as possible from blood 

 cells, is mixed, on a slide, with a drop of India ink (best variety 

 is "Chin chin" Giinther-Wagner Liquid Pearl ink), and the mixture 



22 See Levaditi and BanfcowsTci: Ann de 1'Inst. Past., 1913, XXVII, p. 583. 



