TREPONEMATA 585 
hours in the following solution, which must be freshly prepared each 
time; Giemsa's solution, 10 drops; 1 per cent aqueous solution of 
potassium carbonate, 10 drops; distilled water, 10 cc. The films, 
after staining, are washed in distilled water. If overstaining has 
taken place the film may be left in distilled water for some minutes 
until a sufficient amount of stain has been removed. The preparation 
is then dried and examined. The organisms appear as purple or \ioIet 
spirals on a bluish background. 
Silver Imprecjnation Method} — y^ot generally used. 
2. Cultural Diagnosis. — '^ot practical for routine. 
3. Serum Diagnosis. — (Vor Technique see pages 160, 170). 
P^or a time the specificity of the Wassermann reaction for syphilis 
was questioned, because it was found that alcoholic extracts of normal 
heart could be substituted for extracts of luetic organs as antigens. 
A careful study of thousands of cases has shown, however, that a vast 
majority of acti\'e syphilitic infections, especially those in the second- 
ary stage, give both a Kahn test and a positive Wassermann reaction. 
During the earlier part of the primary stage these reactions are fre- 
quently negative. In the tertiary stage the reactions are frequently 
positive and the spinal fluid frequently gives a positive reaction as well. 
Occasionally cases of frambesia and of leprosy give a positive Wasser- 
mann reaction, but these diseases are rare in temperate climates. 
Statistics indicate that the Kahn test and Wassermann reaction 
disappear when a cure is effected, but they reappear if the disease 
again becomes active. It is important to remember that the mercurial 
treatment tends to diminish the intensity of these reactions, and they 
may even disappear temporarily. Treatment with arsphenamine and 
neoarsphenamine may accentuate the reactions, temporarily at least. 
The Influence of Alcohol Upon the Wassermann Reaction.— Craig 
and Nichols^ have found that the ingestion of alcohol may temporarily 
change the Wassermann reaction in a patient from a positive to a 
faintly positive or a negative reaction. The full effect of the alcohol 
in depressing the reaction is usually manifested within twenty-four 
hours, and the reaction may remain negative for as long a period as 
three days after alcohol is discontinuefl. Beer, wine or whisky may 
be effective. The amount of alcohol that will effect the change in 
reaction is not definitely known, although the equivalent of 90 cc. 
of 95 per cent alcohol was sufficient in one particular case. The sup- 
pression of the reaction is not due to the concentration of alcohol in 
the blood; Craig and Nichols believe the lipotropic substances of the 
blood are weakened or destroyed. 
There is no doubt that both the Kahn test and the Wassermann reac- 
tion carefully executed by competent workers are the most delicate and 
reliable diagnostic methods for syphilis known at the present time. 
The Kahn test, however, is much simpler and quite as reliable and 
accurate. 
1 See Levaditi (Compt. rend, de Soc. de biol., 1905, 59, .326) for details. 
- Jour. Am. Med. Assn., 1911, 57, 474. 
