INTRODUCTION. 9 
remained in the same foul state as at first ; whilst new loca- . 
lities have been affected, just in proportion to the degree in 
which they have participated in the same conditions ; and those 
originally attacked have escaped, wherever they had adopted 
the requisite means of purification. Thus, at Newcastle-on- 
Tyne and Gateshead, the first outbreak occurred in the very 
same streets, and even in the same houses, in the three visi- 
tations of 1831, 1848, and 1853. An outbreak which 
occurred in 1853, at Luton, in Bedfordshire,—where, out of 
a population of 126 persons, inhabiting twenty-five houses, 
no fewer than fifty-four attacks of choleraic disease, fifteen of 
them fatal, took place within three weeks,—was most dis- 
tinetly traceable to defect of sewerage, which had been pre- 
viously manifesting its malign influence on the general health 
of the town. And the fearful pestilence which devastated 
the neighbourhood of Golden Square (London) in the autumn 
of 1854, was no less distinctly traceable to the contamination 
of the pump-water by the bursting of a sewer into the well. 
On the other hand, Exeter and Nottingham, which suffered 
severely in the first epidemic, escaped comparatively un- 
harmed in the subsequent visitations; and this result is 
plainly due to the sanitary improvements which had been 
made in the interval. In 1832 there perished of the epide- 
mic in Exeter, as many as 402, out of a population of 
28,000, or no fewer than one in seventy ; and a vast amount of 
suffering, with a heavy expense, was entgiled upon the town. 
Tn 1848-9, on the other hand, out of a population of about 
32,600, there were but 44 deaths, or less than one in seven 
hundred ; and upwards of one-half of these occurred in 
a single parish, that lies very low, and in the midst of putrid 
exhalations from the city drains. In Nottingham, with a 
population of 50,000, there were 296 fatal cases of cholera in 
1832, nearly all of these being in the lower part of the town, 
which was ill-drained, extremely filthy, and densely popu- 
lated ; but in 1848-9, though the population had increased to 
58,000, the number of deaths from cholera was no more than 
8, all of these occurring in localities, which, in spite of what 
been done, retained much of their previous filth. 
The foregoing are only samples of a vast number of cases 
hich might be adduced, in proof of the absolute preventi- 
ity of Cholera, and of other diseases of the same class. It - 
