210 SPIRILLA. 



Tube 3. 1 drop known syphilitic serum + complement + 

 antigen. 



Tube 4- 1 drop known syphilitic serum + complement (no 

 antigen). 



Tube 5. : 1 drop known normal serum -f complement 4 

 antigen. 



Tube 6. 1 drop known normal serum + complement (no 

 antigen). 



Tube 7. Complement alone. 



To each tube 1 c.c. of 1 per cent, emulsion of human cor- 

 puscles is added, and the mixture shaken and placed in an 

 incubator at blood heat for one hour. At the end of one 

 hour two units of amboceptor are added to each tube, and 

 incubation again resorted to for one hour. In tube 3 certainly, 

 and in tube 1 if the patient's serum is syphilitic, no haemolysis 

 will take place, for the complement will be bound, as explained 

 before. If patient's serum is not syphilitic, haemolysis will 

 take place in tube 1 . By drying amboceptors and antigen in 

 measured quantities on blotting- or filter-paper, Noguchi has 

 further simplified the technique, as well as furnishing staple 

 reagents. 



The substances needed for the above tests are prepared as 

 follows : 



1. Patient's serum. 



2. Fresh guinea-pig serum, obtained by bleeding a guinea- 

 pig into a sterile Petri dish. For making the test 0.1 c.c. of 

 a mixture of 1 c.c. of serum to 1.5 c.c. of normal salt solution 

 is used. 



3. Antigen. This consists of the acetone insoluble residue 

 of syphilitic organs which have been previously macerated and 

 extracted with alcohol, evaporated, dissolved in ether, and pre- 

 cipitated by acetone. This residue is dissolved in ether and 

 mixed by shaking with salt solution until the ether has evap- 

 orated. About 0.2 grani of the sticky residue is used to the 

 100 c.c. of salt solution. In its finished state it is opalescent 

 green without sediment. 



4. Human Corpuseles. (This is the essential of Noguchi's 

 modification, as the patient's own corpuscles may be used in- 



