APPENDIX 267 



Cultures should be made on blood-serum, and should not be less 

 than nine nor more than twenty-four hours old. Films are spread 

 in the ordinary way and stained for half a minute in— 



Methylene blue i gramme. 



Alcohol (96 per cent.) 20 c.c. 



Glacial acetic acid cq c.c. 



Water g^o c.c. 



They are then washed and treated for half a minute with— 



Bismarck brown 5 grammes. 



Water 1,000 c.c. 



The polar bodies are small spheres which are contained in the 

 bacilli, there being usually two in each bacillus, one at each end. 

 In a film specimen of the true diphtheria bacillus stained in this 

 way they appear as very minute dark blue or black dots, which 

 may easily be mistaken for cocci ; the bodies of the bacilli are 

 often almost invisible. According to some authorities, the 

 presence of these granules in young cultures of bacilli which 

 present the morphological characters of the diphtheria bacillus is 

 proof of their virulence, whilst their absence proves the cultures 

 to be of the non-virulent "pseudo-diphtheria" bacillus. The 

 method can also be applied to films made directly from the swabs, 

 and recent researches seem to prove that the results thus obtained 

 are of considerable diagnostic value. 



If this method be adopted the films must be very carefully 

 searched, as it often happens that characteristically stained bacilli 

 may be seen in one part of the field, while they are entirely absent 

 elsewhere. This is especially true of films made direct from the 

 swabs. 



The author is inclined to attach very considerable importance 

 to a positive result obtained with this method of staining, but 

 would not consider a negative result as indicating the absence of 

 the diphtheria bacillus. 



Ill 



Leishman's Method of Staining the SpirocH/Ete of 

 Syphilis. 



I have seen better specimens of the spirochsete obtained by 

 this method than by any other, but my own results have been less 

 satisfactory. Prepare films in the usual manner, allow them to 



