BACOT : MOSQUITOES AND THE DANGER OF MALARIA. 253 
varied in Huntingdon from 2.3 to 34.09 per 1,000 ; at Wisbeach, 
from none to 9.1 per 1,000 ; at North Aylsham, from none to 
37.3 per 1,000. 
During the latter Half of the nineteenth century, the disease 
gradually died down. This was due in part, it is thought, to 
improved drainage leading to a reduction in the numbers of 
mosquitoes : possibly also to the very general use of quinine, 
restricting the opportunities of the mosquitoes becoming infected. 
The action of quinine is to kill off the organisms in the blood 
of the patient ; hence the fever is abated ; and, when mosquitoes 
feed on the blood of the patient, they do not ingest the organism 
and become infective. 
When Dr. Whitley made his report to the Privy Council 
in 1864, 1 Ague had already very greatly decreased, though it 
still lingered on in a few of its old haunts. 
I have personally some testimony in respect of the south¬ 
eastern portion of Essex. One of your members, Mr. Thomas 
Barrett-Leonard, of Aveley, who was unable to attend to-night, 
wrote to me on the subject, and he has kindly allowed me to 
quote from his letter :— 
“ When I was a boy, Ague was fairly common here. I remember my 
mother used to dose workmen on the estate with port and quinine, and 
she suffered from it rather badly herself. 
“ My father tells me that, when he was young, people used to say, 
* Have you had your Ague this Spring ? ’ My great grandfather said 
he would give up going to Court, as George III. annoyed him by asking 
always about his Ague." 
" I cannot altogether believe Defoe’s account in his Tour Through 
the Whole Island of Great Britain , published in London (4 vols., 1724-27), as 
to the effects of Ague in the marshlands of Essex at that period, but I 
suppose there is this amount of truth in the stories, viz.: —that there 
was a considerable mortality among persons going to live at such places 
as Fobbing, Mucking, Canvey Island, etc. I believe there is practically 
no Ague now-a-days in South Essex: anyhow there is none in Aveley. 
How has this change come about ? The marshes have been drained 
for the last 300 years in the same manner as now.” 
I can myself add this further testimony :—Some twenty-five 
years ago, when I used to go moth-hunting in the district between 
Rayleigh and Thundersley, I contracted a feverish attack which 
my doctor diagnosed as Ague. It yielded readily to quinine, 
but I had two recrudescences of the symptoms in subsequent 
years, following violent exercise and exposure to chills. 
1 ‘ Residence in Marsh Districts ’’ (Reforts from Commissioners, xxviii. p. 430 6 
