All the instances of communication of cholera through the medium of water, above related, have resulted from the contamination of a pump-well, or some other limited supply of water; and the outbreaks of cholera connected with the contamination, though sudden and intense, have been limited also; but when the water of a river becomes infected with the cholera evacuations emptied from on board ship, or passing down drains and sewers, the communication of the disease, though generally less sudden and violent, is much more widely extended; more especially when the river water is distributed by the steam engine and pipes connected with waterworks. Cholera may linger in the courts and alleys crowded with the poor, for reasons previously pointed out, but I know of no instance in which it has been generally spread through a town or neighbourhood, amongst all classes of the community, in which the drinking water has not been the medium of its diffusion. Each epidemic of cholera in London has borne a strict relation to the nature of the water supply of its different districts, being modified only by poverty, and the crowding and want of cleanliness which always attend it. [Sidenote: THE EPIDEMIC OF 1832.] The following table shows the number of deaths from cholera in the various districts of London in 1832, together with the nature of the water supply at that period. (See next page.)[11] This table shows that in the greater part of Southwark, which was supplied with worse water than any other part of the metropolis, the mortality from cholera was also much higher than anywhere else. The other south districts, supplied with water obtained at points higher up the Thames, and containing consequently less impurity, were less affected. On the north of the Thames, the east districts, supplied, in 1832, with water from the river Lea, at Old Ford, where it contained the sewage of a large population, suffered more than other parts on the north side of London. Whitechapel suffered more than the other east districts; probably not more from the poverty and crowded state of the population, than from the great number of mariners, coalheavers, and others, living there, who were employed on the Thames, and got their water, whilst at work, direct from the river. There were one hundred and thirty-nine deaths from cholera amongst persons afloat on the Thames. The cholera passed very lightly over most of the districts supplied by the New River Company. St. Giles’ was an exception, owing to the overcrowding of the common lodging-houses in the part of the parish called the Rookery. The City of London also suffered severely in 1832. Now when the engine at Broken Wharf was employed to draw water from the Thames, this water was supplied more particularly to the City, and not at all to the higher districts supplied by the New River Company. This would offer an explanation of the high mortality from cholera in the