Difficulties in the formulation of the Wasserman reaction: the multitude of ingredients, the complexity of their manufacture and determination of their dosage, the need to keep experimental animals, the inconstancy of individual elements (complement, lamb erythrocytes) have been put forward since 1918, for serodiagnosis of syphilis many sedimentary reactions or otherwise flocculation reactions: reactions C. Bruck'a, Sachs Georgi, C. Meinicke, Kahn'a and others.