xv
This method was adopted by the authors and a few others who have done parallel tests
comparing it with the original Wassermann. They state that the test gave highly reliable
results in their hands. The advantages they claim for this method are (1) the simplicity of the
technique which renders the test accessible to the general practitioner who is without laboratory
facilities. (2) It requires a very small amount of blood from a patient. The method has not
given at all satisfactory results in my hands. The defects of the method which were
admitted by the authors to be present in about 10 per cent. of cases such as (1) deficiency of the
natural hæmolytic power of human serum for sheep's corpuscles and (2) deficiency and easy
deterioration of complement naturally present in the serum, seem to be intensified in this
country. This is probably due to the higher temperature of the country and a natural deficiency
of Indian blood in there constituents. These factors should be investigated. In a large percent-
age of cases the control test for the presence of complement and immune body in the serum does
not answer at all. The remedies suggested by the authors of (1) doing the test again with fresh
blood serum drawn on another occasion from the patient and (2) supplying the deficiency by
adding one volume of inactivated normal human serum which is known to be lytic for sheep's
corpuscles, have not effectively cured the defect in my cases. On the other hand the advantages
claimed are not of very great weight. 2 to 3 c.c. of blood can be very easily taken from a finger
as pointed out above and blood can be taken to the extent of 30 to 40 c c. from a rabbit's heart
without hurting the animal in the least, as is the usual way adopted in this laboratory.
Further, a definite and conclusive result from a laboratory will be more acceptable to both
patient and physician than a vague indefinite result.
For a critical study of the comparative merits of the three methods, I have not sufficient
material available. A series of parallel experiments on the lines of each method should have
been done simultaneously with the same serum and the results compared. The different methods
adopted in the examination of the sera in this laboratory were more an outcome of necessity
than a piece of research. The Hecht-Fleming method gave indefinite results in about 37 per
cent. of bloods and in consequence was replaced by the original Wassermann. After a time our
stock of the principal reagent, extract of syphilitic liver, was exhausted and no fresh material
was available for a long time. The delay was keenly felt and caused great inconvenience and
this induced me to try Levaditi's modification, the materials for which were available at all times.
Thus methods were adopted in succession and the bloods examined by each were different and
gave no comparative indication regarding the value of each method in specific cases. However
at each time of passing from one method to another a few specimens were examined by the two
methods in question at the time. Although the information available under these heads is very
meagre, it indicates the necessity for a separate research on the subject. I therefore append in
two small tables the results of such comparative examination.
Seventy-eight bloods were examined by the Hecht-Fleming method with 29·5 per cent.
positive, 33·3 per cent. negative, and 37·2 per cent. indefinite results. The 37 per cent. of indefi-
nite results renders the method very unsatisfactory. In as far as the positive results were
concerned, the method was reliable and consistent with the clinical diagnoses. In all three modifica-
tions a negative reaction does not necessarily exclude syphilis. By the original method a larger
number of bloods, 292 in number, were examined with 64 per cent. giving positive results, 35·6
per cent. negative and 0·4 per cent. indefinite results. The indefinite results were practically
negligible. One hundred and eleven bloods were examined by Levaditi's modification with
42·3 per cent. positive and 57·7 per cent. negative results. This test gave no indefinite results.
TABLE III.
The above table gives the analysis of eight bloods examined by the Hecht-Fleming and the
original methods at the same time. Of these, six bloods gave an indefinite result with the former
while all of them gave a definite result with the latter; three of these definite results were positive,
so three out of eight, i.e. , 37·5 per cent. of positive reactions were missed by the Hecht-Fleming
method.