182 Miscellaneous Notices Respecting Cholera. 
of the disease or knowledge of its origin. I think the following con- 
clusions may be relied upon as far as relates to England. ‘The sides 
of rivers and the vicinity of low marshy grounds were the chief seats 
of the disease. In towns which were somewhat elevated above the 
river level, it was chiefly in those streets that descended to the river 
that the cholera prevailed. Chalk soils and dry sandy soils seem to 
have been peculiarly exempt from cholera. There has not been one 
case of Indian Cholera in the whole county of Sussex. At Hamp- 
stead, though so near London, we had only two cases and these were 
of persons who resided the greater part of the day in London. Hamp- 
stead contains 8000 inhabitants, it is upon the London clay chiefly, 
but this is much mixed with sand and we are elevated from 300 feet 
to 350 feet above the Thames. 
Medical Geology.—At some future day, I have no doubt, that we 
shall discover that there is such a science as medical geology, viz. 
that certain strata are, as foundation ground for human habitations, 
much more liable to be affected ‘with certain causes of diseases than 
others, and we shall probably not only know the fact, but ascertain 
the cause and the remedy. The. county of Norfolk has long. been 
famous or infamous for the astonishing number of patients affected 
with the stone, nothing has hitherto been done to investigate the cause. 
The earth, I have long since. been persuaded, contains within itself 
agents destined to affect future changes of the solid surface, and also 
of the atmosphere. The pestilence and earthquake which reigned 
together, for seventy years during the reign of Justinian, and depop- 
ulated the fairest portion of the civilized world—were doubtless the 
result of certain subterranean laws, which regulate its internal eeono- 
my—laws known only to its creator. 
Celestial Phenomena.—Beside the cholera, we have in Europe, 
been terror-stricken by the comet, which passed the earth’s path in Oc- 
tober, You are, no doubt, well acquainted with Arago’s popular es- 
say on comets ; | am however by no means convinced that the chan- 
ces of the earth or atmosphere being affected by the near approach 
of a comet are so slight as he would have us believe. In the sec- 
tion of the essays on the four new planets, “ that move round the sun 
in nearly the same time and distances, he agrees with other astrono- 
mers in supposing they may all be some broken parts of one planet— 
and that this may have been effected by a comet, or by an iuternal 
explosion, but then the difficulty he says is in supposing how it should 
happen that while three of these planets have taken a large portion of 
