Since recognition of the Spirochæta pallida as the probable cause of syphilis, now five and a half years ago, the staining methods, as has been said, are almost as numerous as the investigators who have studied it. Out of the many, there is one which has of late been especially prominent. I refer to the India-ink method first recommended by Burri,1 and since by a number of other investigators.
This method, which consists in mixing the serum with diluted India ink on a glass slide and allowing it to dry in the air, is so easily carried out and requires so little technic, that its use, sooner or later, would have become quite universal. Recently, I used this method on a number of occasions, and I desire to relate my experience with it.
In one patient who had a typical case of syphilis, I found true spirochetes with the
BARACH JH. WARNING AGAINST THE INDIA-INK METHOD FOR THE SPIROCHÆTA PALLIDA. JAMA. 1910;55(22):1892–1893. doi:10.1001/jama.1910.04330220036015