The Hemolytic Amboceptor 301 



bulk of fluid to 5 cc, in the latter makes it necessary to add i more 

 cubic cemtimeter of salt solution to each tube. We aim to have 

 exactly 5 cc. of fluid in each tube. 



The tubes are again stood in the thermostat, where they are per- 

 mitted to remain for two hours, when the readings are taken and 

 carefully noted. After this the rack and all the tubes are placed 

 in the ice-box until twenty-four hours old, when the final readings 

 are taken and the conclusions are reached. 



As a rule, the readings taken after the second hour of incubation 

 and those taken after twenty-four hours correspond. 



A vahd test should show the following: 



Tubes 



1. No hemolysis in syphilis. Hemolysis in health. 



2. Complete hemolysis. 

 3- No hemolysis (this is the standard of comparison). 



4. Complete hemolysis. 

 Test Controls. ] 5. " " 



6. 



5. " _ " 

 9. No hemolysis, as a rule. 



In the tubes in which hemolysis takes place the change is very 

 marked. The hemoglobin dissolves out of the corpuscular stroma 

 .and saturates the fluid, transforming it from the opaque pale red 

 to a transparent Burgundy red. Sometimes the corpuscular 

 stroma dissolves, sometimes it sediments as a colorless mass to the 

 bottom of the tube. . , ; 1 



In the tubes containing the positive or syphilitic Serum, and in 

 which there is complete complement fixation, the unaltered corpus- 

 cles sediment to the bottom of the tube, leaving a colorless fluid 

 above. 



When the complement fixation is complete there is no solution 

 of the hemoglobin. Such a result has been described by Citron as 

 + -f- -{- -f. When the sedimented corpuscles lie at the bottom of a 

 slightly reddened fluid, the result is said to be 4- -f -|- ; when at the 

 bottom of a distinctly red fluid, + +, etc. Confusion will be 

 avoided by making reports as positive in all cases in which there is 

 a distinct red corpuscular deposit, regardless of the state of the 

 supernatant fluid, and negative when there is no such deposit. 



When we come to inquire why the supernatant fluid should be 

 red, we reach a question that is not quickly answered. In order 

 • to be in a position to explain it in certain cases we introduced in our 

 series tube 9, by which to discover whether the serum under examina- 

 tion contains, as is sometimes the case, in health as well as in syphihs, 

 sheep corpuscle amboceptors. If tube 9 shows such amboceptors 

 to be in the serum, it explains the redness of the fluid bathing the 

 corpuscles, and does not invalidate the test. If no such amboceptors 

 are present and the fluid is still red, it may indicate that a little of 



