267 
SOME ENUMERATIVE STUDIES ON 
MALARIAL FEVER 
BY 
Major RONALD ROSS, F.R.S., 
AND 
DAVID THOMSON, M.B., Ch.B., D.P.H. 
( Received for publication 15 November, 1910)* 
1. Preliminary . For many years past little information which 
is both new and exact has been added to our knowledge of the 
pathology of malaria. This has probably been due to the 
exhaustion of the older methods of research which, being purely 
qualitative, have failed to indicate the precise correlations between 
the numbers of the parasites present in a patient and the various 
pathological and therapeutical reactions. For example, out of 
fifty-one and thirty-eight successful inoculations of men by means 
of infected blood and infected Anophelines respectively, in not a 
single one has any exact estimate been given of the number of 
parasites inoculated or recovered after the lapse of the incubation 
period; and, though many researches on quinine have been made, 
we know of none in which its direct effect upon the numbers of the 
parasites in the patient has been correctly measured. Moreover, 
the older methods often failed to reveal the parasites at all, unless 
they were present in large numbers. Hence our first care was to 
elaborate more exact methods both for detection and for enumeration. 
This was done early in the year (by R.R. and D.T.), though we 
have by no means reached finality yet. The new methods were 
next employed for all the cases in the Tropical Ward, daily counts 
of the parasites and often of the leucocytes, together with other 
estimations, being made (by D.T.). At the same time parallel 
chemical studies were carried out and therapeutical ones, and the 
measurements were carefully charted and compared. Even at 
this preliminary stage the results (which are given at the end of 
this paper) include more accurate verifications of some old 
conjectures, and demonstrations of some new theorems. 
V 1 1 v-vv ^ ore Royal Society, Dec. 8th, and reprinted from Proc. Roy. Soc., Series B-, 
0 XXXIII, p. 159, w ith Addenda.) 
R 
