Another point brought forward by the Bills of Mortality
is, that a deficiency in the vegetable diet of Londoners may
have conduced to debility that may have rendered them more
susceptible of contagion or infection. From 1629 to 1750
scurvy was a direct cause of death, and as that disease is so *
rarely fatal ashore, it may be inferred that a few deaths from
it indicate a wide spread of the diathesis. The deaths by it
were numerous up to 1690, after which they fell rapidly in
number, so that up to 1750 they rarely touched the pro-
portion of 0*1 per 1,000; i.e.y of one in ten thousand of total
deaths, which proves the advance of horticulture between
the reigns of Charles I and George II.
Mr. President and Gentlemen, I shall now endeavour to
present to your notice a crude arrangement in cycles, or
eras, of those epidemics that have been recorded in London,
sometimes in it alone, and sometimes in great part over the
whole of the country.
\st Cycle. — From the ninth to the end of the thirteenth
century, embracing the periods when the eastern and southern
counties were constantly harassed by the Danes ; that of the
Conquest and its terrible sequences ; that of the wars be-
tween king and nobles, when the face of the land became
dotted with castles and strongholds, around which the serfs
or cultivators crowded for safety, not daring to wander far
from them to plough the soil. Then were the crusades, the
wars in Ireland, Wales, and Scotland, all of which diminished
the productiveness of the fields by the abstraction of hands.
