In order that treatment of congenital syphilis may be begun at the earliest possible moment, an accurate method of diagnosis in the first few months of life—the so-called period of doubt—is of great importance. Faber and Black1 have done much to clarify the significance of a positive Wassermann reaction of the blood in this period. According to these authors, the use of a quantitative rather than a qualitative technic for testing the blood of infants of syphilitic mothers offers a means of early differentiation between infants who have been infected with syphilis and those who have not. This idea was set forth by Faber and Black as follows:
Our hypothesis in using the quantitative method was that with an initially positive reaction to a routine Wassermann test in an infant at or near the time of birth successive quantitative tests might reveal a progressive decline in titer to zero