Ronald Ross Nobel Lecture

    R E S E A R C H E S   O N   M A L A R I A

93

the insects, and their connection with rank tropical vegetation; we disposed of

the ideas that tidal swamps cause malaria, but showed how earth-works pro-

duce outbreaks by the formation of pools of rainwater. In fact we were able to

give a thorough explanation of the manner in which the old paludic and tel-

luric theories of malaria originated.

We were also able to establish for the first time the fundamental principles

which the State must adopt in order to extirpate malaria in tropical cities.

These are (1) scrupulous drainage of the soil; (2) pending this, the persistent

treatment of Anopheles’ breeding-pools by culicicides; (3) the segregation of

Europeans. We also recommended the protection of public buildings, such

as barracks, gaols, hospitals, and rest-houses by wire gauze screens; the isola-

tion of the sick; and the habitual employment of mosquito-nets and punkahs

by individuals.

Our results and recommendations were immediately communicated to

Government and also published in the medical press

60

.

After our return to England in October we published a full report of our

experiences

6 7

. In this book, written by myself and endorsed by my colleagues,

I collected the principal results of all my researches on malaria made during

seven years; and illustrated the life-history both of the human and avian para-

sites in mosquitoes by numerous photo-micrographs made by myself. This

work, therefore, which records the completion of these labours by the success-

ful demonstration of the whole evolution of the human parasites in Anopheles,

constitutes the summary and conclusion of all my previous papers. It has been

said that the book was based on the writings of those who, as a matter of fact,

learnt everything from me; but I can say with exact truth that if no one except

MacCallum and Koch had touched the subject since 1895, scarcely a word in

the Report would have been different.

It should be added that in March 1900 I gave an abstract of the history of

my work in a lecture at the Royal Institution

68

; and particularly, that toward

the end of the same year the President of the Royal Society, Lord Lister, for-

mally accepted my results in his Address to the Society.

From this time my own efforts have been devoted almost entirely to the

practical campaign against malaria. Few people are aware of the fact that even

the most solid discoveries of science may be allowed by the public to remain

quite disused and inoperative unless strenuous efforts are made to urge them

upon the popular attention. Even yet, in spite of the constant endeavours of

many persons, very little has really been done towards the extirpation of mala-

ria. This has been principally due to the fact that, for some inexplicable reason

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94

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which wholly escapes me, the chief prophylactic measure recommended by

me, namely a campaign against mosquitoes by drainage and petrolage, has

been generally held to be impossible; yet it is the only general prophylactic

measure possible in tropical towns. The struggle over this matter has been al-

most as severe as that over the original problem; but it is now drawing to a

close. It is impossible to discuss the matter here. Suffice it to say that in the two

principal towns, Havana and Ismailia, in which the measure has been ade-

quately employed, the reduction of malaria has already been as much as eighty

per cent.

This then is the conclusion of the history. I fear that some of the personal

details may have appeared out of place in the narrative; but they have been

introduced - though unwillingly - for a special reason. No form of enterprise

is of such transcendent importance to humanity in general as the investigation

of disease - the principal enemy of every man. The interests of all nations, not

only in the present but in the future, demand that every possible encourage-

ment should be given to such investigations - particularly that medical men,

who are in an excellent position to undertake them, shall receive the warmest

assistance in their self-imposed task. The story, however, which I have felt it a

duty to record in this lecture adds but one to the many instances of medical

history which show that little attention is given to this point. My labours will

be abundantly repaid   if earnest students in this field of science receive, in the

future, in consequence of this narrative, a little more assistance than was given

to me.

23. Confirmation and extensions. 

It is impossible for me to describe here, even in

detail, the vast amount of work which has been done in many parts of the

world on the mosquito theory of malaria since 1899; but it is necessary just to

touch upon some of the more immediate verifications of my observations.

(1) Undoubtedly the first verification was due to Koch and his assist-

ants

63,64

. Professor Koch was kind enough to communicate to me at my re-

quest, in a letter dated the 15th May 1901, the origin and progress of his re-

searches on the mosquito theory of malaria. He says:

"The idea that mosquitoes may be the cause of malarial infection occurred

to me on my first visit to the tropics in British India in the winter of 1883-1884,

and since then I have always spoken in this sense in my lectures and to my as-

sistants. I have not indeed myself published anything about these views; but

you will find a notice in R. Pfeiffer’s work Beiträge 

Z

ur Protozoen-Forschung,

Berlin, 1892 (near the end).

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