LETTERS FROM THE REV. WM. DERHAM, D.D. 173 
My head is so bad, y 4 I hope you will excuse me for forgetting 
divers things I have to say, as I am sure I have done. 
One thing I intended to sav, but had like to have forgotten is, 
that I shall be glad to perswade you to be a Member of the Royal 
Society. That you may see how hon ble & ingenious persons many 
of them are w th w ch you are to associate, I have sent you the last 
years List of them. 
Derham, like most inhabitants in those times of the districts 
of Essex near to the Thames, appears to have suffered greatly 
from ague, as did also his correspondent, Dacre Barrett. I can 
remember when ague was common round Belhus, and my father 
when it was pretty general, but now a case is quite rare. The 
reason for its disappearance of late years is not easyto understand, 
as no fresh drainage has taken place in that district, nor has any 
special war been waged against the mosquitoes, which, according 
to recent discoveries, are the origin of that scourge. John Norden, 
in his description of Essex written in 1594, speaks of contracting 
while there “a moste cruelle quartene fever,” while Arthur Young, 
writing nearly 200 years later, does not give the climate of the 
Essex Marsh country a much better character ; yet in their days 
the marshes were drained much as they are now. Indeed the 
word “ Marsh ” as applied to those broad stretches of meadows 
bordering on the Thames is a misnomer, as they are dry, and 
intersected with drains with no boggy spots. The word “ Levels,” 
as the late Rev. W. Palin 5 used to contend, would seem more 
appropriate to them than that of “ Marshes.” 
The relative values of Plot’s Histories of Oxford and Stafford¬ 
shire appear to have been reversed since the Doctor wrote. In 
those days the former was evidently more costly than the latter ; 
whereas of late years the Staffordshire history has been sold at 
prices varying from £21 to £2 2s., and that of Oxford from 
£4 4 S to £1 IS. 
The proper title of the book he speaks of as “ Willoughbie 
and Ray on Birds ” is Ornithologiae Libri Tres, Totum Opus 
Recognovit Digessit Supplevit J. Raius, published 1767. 
Francis Willoughby—1635-1672—was a Warwickshire Squire 
and, comparatively speaking, a rich man. A great friend of John 
Ray, with whom he travelled on the Continent. 
They collaborated in writing the above work ; and Ray 
always acknowledged that he got much of the material for other 
5 Author of Stitford ami its Neighbourhood, etc. 
