230 EEV. W. THORP, B.A. — AGRICULTURAL GEOLOGY, ETC. 
Halifax, in every ten years 17430 persons more in proportion would 
be destroyed by disease." Leeds and Sheffield are built upon exactly 
the same strata which are continuous from one place to the other, 
and the reason of their unhealthiness is because they are located 
upon ' clays and binds ' of the coal formation, which presents certain 
conditions prejudicial to health. The strata are more or less imper- 
vious to water, and consequently the drainage is less efficient. The 
houses are built of brick, and the rooms are smaller, and there are 
large numbers of cellar dwellings. The sewerage being defective, 
there is more malaria and all its evil consequences. Hull and New- 
castle built on clays are more unhealthy than Leeds and Sheffield ; 
whilst the Oolite regions, which are very porous and consequently 
healthy, of Easingwold, Helmsley, Pickering, Malton, &c., stand as 
low as 1 in 55, and are more healthy than Huddersfield and Halifax. 
On the conclusion of Mr. Thorp's paper. Dr. Crowther stated 
that in his opinion a deficiency of water caused a great mortality. He 
had no faith in the notion that high and airy situations were always 
the best. Ardsley, a supposed healthy situation on a hill, was hardly 
ever free from typhus fever, whilst at Wakefield, in the valley, there 
was scarcely ever a case ; thus, in his opinion, proving that it was 
water, and plenty of it, which was wanted. He did not think the 
quality was so much an object as the quantity. j\Ir. Crowther further 
stated that some thirty years ago an epidemic broke out every year 
at Daw Green, near Dewsbury. The inhabitants had an ashes heap, 
and it was customary to remove the ashes every May, and immediately 
the disease was raging. One year it was removed at Christmas, and 
the following summer the place was healthy. The ashes were always 
afterwards removed at Christmas. He maintained that the drainage 
of towns had much influence upon health. In his opinion no good 
would be done until the legislature compelled towns to apply proper ' 
drainage. None but compulsory measures would effect the desired 
good. Mr. C. Morton asked the author of the paper if there was 
any established relation between mortality and the geological position 
of towns. . Mr. Briggs considered that the quality of water had 
more to do with the health of the inhabitants of a district than was 
generally thought, and Dr. Ingiis, of Halifax, stated that the quality 
