Kahn precipitation test for syphilis—improved procedure

The precipitation test for syphilis proposed by the author 1 called forth favorable comment from a number of investigators (Keim and Wile, 2 Herrold, 3 Young, 4 Ide and Smith, 5 Holmes 6 and Levin 7 ). Since the publication of the preliminary studies, however, several observations have been made which led to some changes in the original procedure; also, a modified technic has been evolved which is employed as a check on the original one. The improved method discussed in the following resumé embraces both the original and modified procedures.