The volcanic origin of epidemics / by John Parkin.

  • John Parkin
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: The volcanic origin of epidemics / by John Parkin. Source: Wellcome Collection.

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    t great heat, and by southerly winds. But heat alone can- not be the cause of epidemic diseases, for they sometimes make their appearance in the middle of winter, independ- ently of the fact, that they prevail in all situations and in all latitudes. The pestilence of a.d. 543, according to Procopius, invaded some places in the summer, and others in the winter. Evagrius makes the same remark of the plague of 590. This was also the case with the plague of the 14th century; while the pestilence of 1591 raged in Revel, in the 59th degree of north latitude, in the midst of a severe winter. Small-pox assumes as severe a form in the Arctic regions as within the Tropics ; while the plague has committed as great ravages in Russia, even in the midst of winter, as in Egypt. Although confined, in the present da}7, to the region of the Mediterranean, the plague appears there under very different atmospherical conditions. At Constantinople, it usually breaks out in July, when the temperature is about 95° F.; but, in Egypt, it commences in November, when the thermometer is as low as 68° F. The epidemic cholera, also, on its first invasion, broke out at St. Petersburg, in the middle of winter, and with the thermometer 20° below the freez- ing-point. Heat, therefore, cannot be an exciting cause of epidemic diseases. Nor can a dry state of the atmosphere have more influence in the production of these diseases, for they sometimes prevail in the very opposite condition, or that of extreme moisture. Thus, the epidemic cholera commenced in Bengal, on its first invasion in 1817, in the height of the monsoon, or the rainy season, and when the country about Jessore was covered with sheets of water from the heavy rains. The plague, also, not only
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