Ronald Ross Nobel Lecture

30

    1 9 0 2   R . R O S S

teresting example of the manner in which the human mind is apt to embroider

fact with hypothesis. It is a fact that malarial fever is connected with stagnant

water; but that the connection is due to an aerial emanation from the stagnant

water was only an hypothesis which has never received experimental verifica-

tion. Nevertheless, it was almost universally accepted until the true explana-

tion of the connection referred to was given in the manner which I shall pres-

ently describe.

The discovery of the pathogenetic organism by Laveran produced but little

change in our ideas on this point. It was simply thought that the parasites

must be capable of saprophytic life in stagnant water, and may enter the body

by the inhalation of watery vapour or by infected drinking water; and, in-

deed, efforts to obtain experimental proof of these conceptions were quickly

made, especially by Calandruccio, Marina

8

, Agenore

7

, and Celli and Mar-

chiafava

4

, who endeavoured to infect healthy persons by means of water

brought from notoriously unhealthy sources. The experiments proved, how-

ever, entirely negative - somewhat to the surprise of those who were acquaint-

ed with them. At the same time parallel enquiries were commenced to ascer-

tain the saprophytic stage of the parasites; and Grassi and Feletti found an

amoeba (Amoeba guttula) which they thought might be the parasites in their

free condition

10

. Their work recalls that of Crudeli and Klebs who, before

Laveran’s discovery, claimed to have found the cause of malaria in the form

of a bacillus which they asserted abounds in the water and soil of malarious

localities, especially in the lowest stratum of the air, and gives typical inter-

mittent fever to rabbits and other animals. All these observations are now

proved to have been unsound.

4. First researches

 in India (1889-1894). It is, I understand, the principal duty of

those who are called to the high honour of presenting the lecture of the Nobel

Medical Prize to give in it an account of their own researches ; and I shall there-

fore begin my personal narrative at this point.* I had entered the medical serv-

* More or less brief abstracts of these investigations have already been published

54,68

, but

their brevity has only had the result of permitting the genesis of many errors regarding

the real nature of the task. I have therefore thought it best to give in this publication a ful-

ler, and indeed almost autobiographical, narrative of the successive events. It is scarcely

possible, except by this means, to present a true picture of the difficulties in the way of re-

solving this intricate problem. As so often happens in science, the most important part of

the investigations really consisted of the initial failures; and I

 

have therefore described

these negative results in as much detail as is given to the discovery of the pigmented cells

and of the life history of Proteosoma which afterwards gave the fundamental solution of

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31

ice of the government of India in the year 1881; but, although many opportu-

nities for studying the malarial problem had been given me, I was not special-

ly attracted to it until the year 1889, when I first began to observe many facts

at variance with the telluric hypothesis which had been instilled into me dur-

ing my curriculum. I noted especially that the disease had a much more limited

and localized prevalence than could be explained on any theory of aerial con-

vection; I found that outbreaks often appeared to occur among troops merely

as the result of chill or fatigue; and that in many instances the symptoms

accorded ill with the classical descriptions. These observations provoked in

me much dissatisfaction with accepted theories; and gradually led me to the

task of reviewing the whole subject by close analysis. Unfortunately at that

time it was extremely difficult to obtain in India any of the more recent liter-

ature on the subject; and even the discovery of Laveran (1880) had scarcely

penetrated there as yet - much less the work of Golgi, Danilewsky, Marchia-

fava and Celli. I was therefore forced to rely almost solely on my own observa-

tions and thoughts; and at first fell into the mistaken conception, parallel with

that of Broussais, that the disease may be due to intestinal auto-intoxication;

and I published some papers supporting this view

12-16

. In 1892, however,

several writers began to ventilate Laveran’s work, but most unfortunately de-

scribed, not the parasites of Laveran, but a number of artifacts.* The error was

speedily detected and exposed

17,18,20,21

; but naturally led me (and many

others in India) to doubt the whole discovery. As happened with many others,

although in pursuance of these studies I had made a laborious examination of

malarial blood for some years, I had failed entirely to find the true parasite at

all.** Up to the year 1894, therefore, my work, though it gave me an invalu-

able training for what was to come, remained in itself quite ineffective.

5. Return to England (1894). 

In 1894 I obtained furlough to England; and im-

mediately on arrival sought the advice of Professor Kanthack. He assured me

that I

 

was mistaken in doubting the truth of Laveran’s discovery, and referred

the problem. It should be added that my work was minutely recorded not so much in

publications, as in a long series of letters to Manson, Laveran, and Nuttall, and that ex-

tracts from these letters are now about to be published, together with reprints of some of

my papers.

* Vandyke Carter had accurately followed Laveran in Bombay in 1887; but I

 

did not

see his work until 1894.

* * As I found subsequently, one reason for this was that I had been working principally

with old aestivo-autumnal infections in which the larger and more obvious parasites

(crescents) were scarce.

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