AGf~ICULTURAL RESEARCH, PUSA.

SPIROCllAETES 411";
the chancl'e, serum exudes, amI if blood-stained,
should be removed with dry gauze until clcar
exudate can be obtained. Some of tItis is then
collected in one or two capillary tubes. Both
ends of the tubes nrc scaled in the flame, and
the specimens Hl'l'I submitted for examination.
Another method of obtaining exudate is to apply
,"pirit to the sorc for a minut.c, wash it. ofT with
saline solution and allow the surface to dry;
this leads to an exudatioll of scrOllS f1uiel, which
is collected and examined.
When the primary sore is in process of healing,
miel'oseopie examination of the exudate may yield
negative results. At this stage spirochaetes may be
found in the fluid aspirated from the huhoes by nwallS
of a syringe.
In t.he secondary stage spirochaetes may also he
demonstrated in the serum from the skin eruption,
and in the exudate from mucous patches, etc. Serum
can be obtained from the skin eruption by scarifying
and" cupping" with a test-tube.
After about two weeks from the onset of the primary
sore, the 'Wassermann reaction can be employed for
diagnosis. The reaction becomes progressively more
pronounced 'with the ad vallee of the disease, and is
usually markedly positi,"e ill the secolldary stage.
Owing to the fact that the reaction may be slow in
developing, if at first a negative result is elicited in the
primary stage, it is essential to repeat the test before
excluding syphilis. A negative reaction in a suspected
case of secondary syphilis is highly significant in
exelllding syphilitic infection, but in supposed latent
or tertiary cases a negative result docs not exclude
the disease.
In cerebra-spinal syphilis both the blood and spinal
fluid should be tested.
In dealing with cases of congenital syphilis in young
infants, the muther's blood should he tested if there is
any di1TIelllty in obtaining a specimen of blood from
the child.