96 
POPULAR SCIENCE REVIEW. 
example of tliis is the Great Plague of London, which was 
caused by the total absence of proper ventilation in the filthy 
and overcrowded hovels in which the greater part of the poorer 
population of London lived, together with the filth and putrefy- 
ing abominations which habitually filled not only the streets 
but even the houses of the lower classes. According to Beman, 
the gaol fever was another disease which, arising from a neglect 
of the vital necessity for fresh air, was, a few centuries ago, an 
object of dread to society. The unfortunate and the criminal 
alike were immured in damp, cold, ill-aired dungeons, and kept 
in a state of inactivity. They inhaled the pent-up noxious effluvia 
emitted from their own bodies ; and, from the want of means 
for personal purification, their clothes and bedding during 
their incarceration became saturated with the fatal exhalations, 
in this condition the miserable prisoners engendered, and be- 
came victims to, a disease of deadly malignity. They sickened, 
and with little apparent illness they died. The prison-house 
was thus the focus of a contagion that spread far and wide 
beyond its walls, and spared few who were so unhappy as to 
come within its influence. It was remarked, that although a 
prisoner happened to escape the infection, his clothes, never- 
theless, emitted a pestilence that scattered death around him 
wherever he went. The assizes held at Oxford in 1577 were 
long remembered, and were called the Black Assizes, from the 
horrible catastrophe produced on that occasion by the gaol 
fever. Baker, in his Chronicle, tells us, that all who were 
present in court died in forty-eight hours — the judge, the 
sheriff, and 300 other persons ! — so terrible was the retribution 
suffered by the community for its hardness of heart in denying 
to criminals even those personal requirements necessary for- 
avoiding disease and preserving life. 
Another similar catastrophe is recorded by Blaine as having 
occurred in 1750. During- the sessions a sickening, nauseous 
smell was experienced by the persons in court, and within a 
week afterwards many who had been present were seized with 
a malignant fever. Among those who died were the Lord 
Mayor, the two judges, an alderman, a barrister, several of the 
jury, and forty other persons. It was remarkable that the 
prisoners who communicated the infection were not themselves 
ill of fever ; and it was still more remarkable that none of those 
who were ill of it (to the greater number of whom it proved 
mortal) communicated it to their families or attendants, which 
showed that persons who were treated in clean and airy apart- 
ments, as those were who fell victims to it, do not communicate 
the disease to those in the constant habit of attending upon 
them. 
Historians relate with just indignation that nearly three hun- 
