INTRODUCTION. 
7 
which it may be safely affirmed, on the basis of actual expe¬ 
rience, that the annual mortality may be reduced, by such 
efficient sanitary measures as render the dwellings of the mass 
of the population fit for human habitation; this would give 
an annual mortality for England and Wales of 260,000, 
showing a saying of 180,000 lives annually in that one por¬ 
tion of the British empire. And it must be remembered 
that this amount of mortality represents a vastly greater 
amount of sickness, since, for every death, there are numerous 
cases of severe illness; so that it would be scarcely too much 
to affirm that at least a million out of the whole number of 
such cases annually occurring, are preventible, like the 
180,000 deaths, by adequate provisions for the supply of pure 
air and water, and by efficient sewerage for the removal of 
decomposing matters. It cannot be doubted that, even in 
a mere pecuniary point of view, the expense of such arrange¬ 
ments would be amply compensated by the prevention of a 
vast amount of .that loss of productive labour of various 
kinds, which is at present due to disease ; and, considered on 
the large scale, as a question of social economy, the import¬ 
ance of sanitary legislation can scarcely be over-rated. But 
much cannot be expected to be done in this direction, until 
such an intelligent 'public opinion shall have been created, by 
the general diffusion of sound physiological information, as 
shall be sufficiently forcible to bear down the self-interested 
opposition of those, who do not see that the value of their 
property will be permanently increased at least in proportion 
to the amount of money judiciously expended upon it. 
A more remarkable illustration of what is to be effected by 
sanitary improvements can scarcely be adduced, than that 
which is presented by the comparison between the locality 
termed “the Potteries,” in the immediate vicinity of Ken¬ 
sington, and the “ Model Lodging-houses,” which have been 
erected in various parts of the Metropolis. The site of the 
group of dwellings constituting the former is far from being 
insalubrious in itself, and rows of handsome houses are rising 
up in its immediate neighbourhood; but the condition of 
these dwellings is most filthy. A few years ago, as many as 
3,000 pigs were kept in this locality (the number has since 
been somewhat diminished) ; and the boiling of fat and other 
offal, which is carried on by some of the pig-feeders, some- 
