CHEMICAL METHODS OF DIAGNOSIS 741 



2. Take a number of test-tubes (6-7 mm. diameter) and pour into each 

 1 c.c. of the lecithin emulsion and 1 c.c. of the suspected serum. As a control 

 prepare similarly a number of tubes but using normal serum. Incubate the 

 tubes for from i-6 hours at 38 C. 



3. On taking the tubes out of the incubator leave them to stand at the 

 temperature of the laboratory before recording the results. The Lubes to 

 which the syphilitic serum has been added will show a precipitate which 

 appears first at the surface. 



Forges' method. Method recommended. The reaction in this case depends 

 upon the use of a solution of glycocholate of sodium. 



1. Prepare immediately before use a solution consisting of : 



Sodium glycocholate (Merck), - 1 gram. 



Distilled water, - - 100 c.c. 



2. Heat the suspected serum for half an hour at 55-56 C. 



3. To each of a series of small test-tubes add : 



Heated serum, - 1 c.c. 



Glycocholate solution, 1 ,, 



Prepare similarly a number of tubes with heated normal serum. 



4. Leave the tubes at the temperature of the laboratory for 20 hours. 

 A precipitate, most distinct at the surface of the mixture, is formed only in 

 those tubes containing the syphilitic serum. 



Klausner's method. Distilled water produces a precipitate when mixed 

 with syphilitic serum. 



1. To a number of small test-tubes add : 



Suspected serum, 0*2 c.c. 



Distilled water, - 0'7 



Prepare a number of tubes with normal serum. 



2. Leave the tubes for a few hours at the temperature of the laboratory 

 and then examine the reaction. The syphilitic serum alone produces a 

 distinct precipitate and renders the mixture cloudy. 



