SYPHILIS 113 



tested for its fermentative reactions. It produces acid on dextrose 

 and maltose, but not on lactose or the other common sugars (saccha- 

 rose, mannite, etc.), whereas the M. catarrhalis has no action on any 

 of these. The gonococcus produces acid on dextrose, nothing on the 

 others. The question is determined by cultures in broth containing 

 no glucose (this can be prepared by inoculating ordinary broth with 

 B. coli and incubating twenty-four hours), to which the sugars required 

 (i per cent.) are added before sterilization (intermittent, in the steam), 

 and ascitic fluid, hydrocele fluid, or blood-serum subsequently. 



SYPHILIS 



It has now been abundantly proved that the Spirochceta 

 pallida (or Treponema pallidum) of Schaudinn is the actual 

 cause of syphilis, and the diagnosis of this disease by the 

 recognition of the causative agent is now practicable in some 

 cases. The organism is a spirochaete, in shape resembling a 

 spirillum, but probably of animal nature (i.e., a protozoon). 

 It is very small, or rather very narrow, and stains with great 

 difficulty; it is this fact which has led to its having been over- 

 looked previously. In length it is about equal to the diameter 

 of a red corpuscle, either more or less; it is made up of about 

 eight or ten close-set curves, and it has sharp ends. These 

 facts are very important, for there are numerous spirochaetes, 

 somewhat similar in appearance, which are frequently found 

 in ulcers of all sorts, in the mouth, etc., and which have no 

 doubt been frequently mistaken for Schaudinn's organism. 

 The main difference is that in the other common spirochaetes 

 (one of which, the commonest, is called S\ refringens, and is 

 closely allied to, or identical with, that of Vincent) the curves 

 are wider. For example, if we found two spirochaetes exactly 

 as long as a red corpuscle is wide, and in one there were 

 eight complete curves and in the latter only three or four, 

 the former would probably be pallida, the latter refringens 

 (Plate V.). The former is also said to look stiffer and to be 

 less easily bent. The staining reactions are different in the 

 two cases, refringens being stained, though not deeply, with 

 borax-methylene blue or dilute carbol fuchsin, whilst the 

 latter is not. 



Method. The examination may be carried out on scrapings 

 from a supposed chancre, secondary ulcer, condyloma, etc.; 

 on juice obtained from an enlarged lymphatic gland by punc- 

 ture with a hypodermic needle ; on the blood expressed from 



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