tested on syphilitic animals, was found to be
extraordinarily efficient in killing the germ of syphilis, even when
used in quantities so small as not to injure the animal. Among other
things, there could be no better example of the importance of animal
experiment in medicine. If the cause of syphilis had not been known, and
the disease not given to animals, the discovery of salvarsan might never
have been made. After extensive experiments on syphilitic rabbits, which
showed that the drug could be given safely in amounts large enough to
cure the animal at a single dose, it was tried on man, two physicians,
Drs. Hoppe and Wittneben, volunteering for the test. When it was found
that the drug did them no harm, it was used on syphilitic patients for
the first time. As soon as its remarkable effect on the disease in them
was fully established, Ehrlich announced the discovery before the
medical society of Magdeburg, and the results were published in one of
the most important of the German medical journals. Ehrlich then sent
out from his own laboratory several thousands of doses of the new drug
to all the principal clinics and large hospitals of the world for an
extended trial. It was not until the results of this trial became
apparent that he permitted its manufacture on a commercial scale. There
could scarcely be a more ideal way of introducing a new form of
treatment than the one adopted by Ehrlich, or one better surrounded by
all the safeguards that conservatism could suggest.

+The Mistaken Conception of "Single Dose Cure."+--In the light of his
experience with salvarsan in animals, Ehrlich hoped to accomplish the
cure of syphilis in man by a single dose of the new drug, as he had been
able to cure it in rabbits. All the earlier use of salvarsan in the
treatment of syphilis was carried out with this idea in view, and the
remarkable way in which the symptoms vanished before the large doses
used encouraged the belief that Ehrlich's ideal for it had been
fulfilled. But it was not long before it was found that syphilis had a
stronger hold on the human body than on animals, and that patients
relapsed after a single dose, either as shown by the blood test or by
the reappearance, after varying intervals, of the eruption or other
symptoms of the disease. Unfortunately, the news of the discovery of
salvarsan, and with it Ehrlich's original idea that it would cure
syphilis by a single dose, had gotten into the newspapers. Numbers of