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-Lennard, 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" (Reports from Commissioners. xxviii. p. 430 6