22 5 
PRELIMINARY EXPERIMENTS ON 
THE EFFECT OF COLD ON VARIOUS 
DISEASES IN SMALL ANIMALS 
BY 
PROFESSOR MAJOR RONALD ROSS, C.B., F.R.S., 
AND 
MAJOR C. L. WILLIAMS, I.M.S. (Retired) 
( Received for publication 11 June, /<?/o) 
Prefatory Note by R. Ross 
Some years ago Sir Edwin Durning-Lawrence, Bart., offered 
funds to the Liverpool School of 1 ropical Medicine for the purpose 
of experimenting on the effect of cold on Yellow Fever—a subject in 
which he had long been interested owing to various reports which had 
come to his knowledge. The School found it difficult to give effect to 
his wishes, and the matter was allowed to drop. 
For a long time I have felt that much experimental work still 
remains to be done regarding the cure of parasitic diseases, especially 
by such simple natural agencies as heat and cold. Most of the animal 
parasites occur most frequently in persons who live in warm climates, 
that is to say, they are accustomed to live in hosts who themselves live 
under conditions favourable to the said parasites. There may be 
reasons for thinking that if these conditions are abruptly altered the 
result will be harmful to the parasites, just as abrupt changes are apt 
to be harmful to higher organisms. Of course, the temperature of 
the patient’s body is not markedly changed by alteration of external 
temperature; but, nevertheless, certain changes may be produced in 
his blood or tissues which are likely to be inimical to parasites living 
in him. I cannot point to any very definite prima facie evidence in 
favour of this view, but some general observations may be mentione 
For example, it is a common custom to send patients suffering from 
malaria to temperate climates, as to the hills in India. From my own 
clinical experience I certainly think it is easiei to treat malaria in 
