NATURAL HISTORY. 
29 
the burials. The Blockhouse Fields are covered by 
one hundred and twenty-seven houses^ with a popu- 
lation of six hundred and forty-seven persons. This 
number gives us five persons to each house. As the 
houses are generally small, and situated in a low 
marshy ground, with a ditch filling the air with its 
pestilential vapour, the mortality in this part of the 
town must be very great. Again, the decrease of 
agricultural labourers must also have the same ten- 
dency. The number of persons employed in agricul- 
ture, to the number employed in trade and manufac- 
tures, is in the following ratio : — 
1811, as 1 to 16.— 1821, as 1 to 22, 
shewing in ten years, a very considerable decrease of 
agriculturists. These causes would tend to counteract 
the influence of the preventive check ; or in other 
words, the effect produced by the decrease in the 
number of marriages, would be counteracted by 
other causes increasing the number of deaths. 
I shall now proceed to give a very brief account of 
the diseases which prevail in the county. 
It appears, from what I have before stated, that 
there is a great variety of soil in the county of 
Worcester, consisting of sand, bogs, debris of rock, 
lime, clay, and loam. Immediately under this soil, 
and the superficial beds of gravel and clay, the princi- 
pal strata of the county are those of the red sand- 
stone formation. 
Dr. Henry, of Manchester, in estimating the 
