i82 AIDS TO BACTERIOLOGY 



glycerin, 250 c.c.; methyl alcohol, 250 c.c. Blood films 

 or smears from chancres are fixed in alcohol for fifteen 

 minutes and then stained in Giemsa stain, diluted to 

 the extent of 1 drop in 1 c.c. of distilled water, and made 

 alkaline with dilute potassium carbonate solution, for 

 five hours or longer. The slides are washed in distilled 

 water and dried. T. pallidum is usually stained a light 

 rose-pink and other spirochsetes and organisms blue. 



Burri's Indian-ink method (p. 48). Gunther-Wagner 

 ink is sterilised by steaming. Sommerville recommends 

 centrifuging the ink until a film made from the upper 

 portion of the column appears under the jVinch ob- 

 jective quite homogeneous. Equal quantities of exudate 

 and ink are mixed and spread on a slide. The preparation 

 is allowed to dry and examined by the oil- immersion 

 lens without a coverslip. The T. pallidum appears as a 

 white, wavy thread in a dark field. Sometimes treponema 

 cannot be discovered in chancres after repeated examina- 

 tions and the cases ultimately prove to be of syphilis. 



The Wassermann reaction (p. 21) is used for diagnosis, 

 and appears to be of most value in the secondary stage 

 of the disease. It is inadvisable to place reliance on a 

 negative reaction in the primary stage, but as the method 

 improves the cases of definite untreated syphilis in which 

 a negative reaction occurs are becoming fewer and fewer. 

 The reaction is positive in both the blood and cerebro- 

 spinal fluid of general paralytics but not at every examina- 

 tion. D'Arcy Power says it is not usually positive until 

 five to eight weeks after infection when the disease has 

 ceased to be local and has become generalised in the body. 

 McDonagh thinks it doubtful whether our present inter- 

 pretations of its results are correct, and succeeded in 

 making a reaction positive or negative at will. H. C. 

 French states that the test may be negative, and later 

 positive, or vice versa, without any material change in 

 the immediate surroundings of the patient. 



Positive Wassermann reactions have been found in 

 cases of non-syphilitic (soft) chancre (French), and also 

 in alopecia areata, gonorrhoea, yaws, leprosy, malaria, 

 puerperal eclampsia, lupus erythematosus, trypano- 

 somiasis, enteric fever, tumours, herpes, aortic disease, 

 relapsing fever, in some persons under narcosis and in 

 serum from dead bodies. Positive results of a transient 



