anifestations were well known and admirably described by
the older writers. In the seventeenth century, as I have already told
you, the remarkable discovery was made that the bark of the cinchona
tree was a specific. Between the date of the Countess's recovery in Lima
and the year 1880 a colossal literature on the disease had accumulated.
Literally thousands of workers had studied the various aspects of its
many problems; the literature of this country, particularly of the
Southern States, in the first half of the last century may be said to
be predominantly malarial. Ordinary observation carried on for long
centuries had done as much as was possible. In 1880, a young French army
surgeon, Laveran by name, working in Algiers, found in the microscopic
examination of the blood that there were little bodies in the red blood
corpuscles, amoeboid in character, which he believed to be the germs of
the disease. Very little attention at first was paid to his work, and it
is not surprising. It was the old story of "Wolf, wolf"; there had been
so many supposed "germs" that the profession had become suspicious.
Several years elapsed before Surgeon-General Sternberg called the
attention of the English-speaking world to Laveran's work: it was taken
up actively in Italy, and in America by Councilman, Abbott and by others
among us in Baltimore. The result of these widespread observations
was the confirmation in every respect of Laveran's discovery of the
association with malaria of a protozoan parasite. This was step
number three. Clinical observation, empirical discovery of the cure,
determination of the presence of a parasite. Two other steps followed
rapidly. Another army surgeon, Ronald Ross, working in India, influenced
by the work of Manson, proved that the disease was transmitted by
certain varieties of mosquitoes. Experiments came in to support the
studies in etiology; two of those may be quoted. Mosquitoes which had
bitten malarial patients in Italy were sent to London and there allowed
to bite Mr. Manson, son of Dr. Manson. This gentleman had not lived out
of England, where there is now no acute malaria. He had been a perfectly
healthy, strong man. In a few days following the bites of the infected
mosquitoes, he had a typical attack of malarial fever.

(3) Journal Linnaean Society, London, 1879, XIV, 304-311.

(4) Medical News, Philadelphia, 1889, LV, 689-693, and monograph
with Kilborne, Washington, 1893.

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