Sanitary engineering : a series of lectures given before the School of military engineering at Chatham, 1876 / by J. Bailey Denton.

  • John Bailey Denton
Date:
1877
Catalogue details

Licence: Public Domain Mark

Credit: Sanitary engineering : a series of lectures given before the School of military engineering at Chatham, 1876 / by J. Bailey Denton. Source: Wellcome Collection.

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    I do not know if any like analysis has been made of the moisture evaporated from the back yards of houses and cottages in some of the filthy towns and villages which exist in this country, but I can well understand that one great cause of disease in Great Britain, in spite of its advantages of climate, is the amount of evaporation which takes place in association with organic emanations, and that it does not require the heat of a southern climate to produce an atmos- pheric condition, differing only in degree from the malaria which we have been accustomed to associate only with distant and hot countries. That heat has an extraordinary influence in promoting malaria wherever organic substances are collected upon a wet soil, I can sup- port bymy own investigations in Italy. Ifouud—in the autumnof 1864 when examining the sea-board marshes between Civita Vecchia and Pcestum for the purpose of ascertaining their capability of growing cotton—that it required neither warning nor guide to enable me to identify infected districts, nor that any one organ or sense alone detected the obnoxious atmosphere. The senses generally became affected. In every instance of infected air with which I then became cognizant the subsoil water was within a little depth of the surface, and the quantity of decomposable organic matter was very large. Such a state of things an English agriculturist would quickly and radically alter—as unprofitable in cultivation, and injurious to vege- tation—by under-drainage. The Italians, however, knowing that the difference between high and low tide in the Mediterranean Sea is practically nothing, and that therefore there was no capability of tidal discharge, instead of raising the injurious waters by steam, as is done in this country, in Holland, and other countries, and discharging them above sea level, adopt the raven scheme of raising the land itself with debris from the Appenines by warping—a process called bonification —which has the effect of covering the surface with solid materia], and of leaving the soil below still saturated with water without eradicating malaria. X.—On Carbonic Acid as the measure of Impurity op Air. If the exact measure of impurity of air was simply that expressed by the increased amount of carbonic acid, or the reduced amount of oxygen which it contains, it would not be long before the engineer, as well as the medical officer, could ascertain the exact condition of the air of any locality. But it is not exactly so. Though the increased amount of carbonic acid is some guide to the extent of impurity existing in the air, it gives no clue to the quality of that impurity, nor can we accept as a rule the assumption that as the