Note 81 — PART I. INTRODUCTION. (continued 2)

“All this tract (of Marshland) and adjoining fens being little higher than the level of the sea, or that of the rivers that pass through the country, was once so exposed to inundations from floods and high tides, that till dikes and drains were made, it was all one large morass; and even now, after so much labour and expence, the country is still liable to be overflowed by extraordinary high tides or floods, or other casual events. By the evaporation of this water, and especially by that of the water of the numerous ditches, in which various plants and insects die and rot, the atmosphere during the latter part of summer and autumn is filled with moisture, and with putrid and insalutary vapours.—Another cause of the insalubrity of the atmosphere is an imperfect ventilation. As there are no hills here to direct the winds in streams upon the lower grounds, the air is apt to stagnate and become unwholesome. An additional cause of the unhealthiness of this flat and marshy country, may be the impurity of the water in common use; for this being either collected from rains, and preserved in cisterns, or drawn from shallow wells, is, in hot and dry-seasons soon corrupted. This being the case, the general tendency to putrefaction must be increased by the use of such water, as well as by the meats, which in a close, hot, and moist air, are quickly tainted. Several circumstances therefore in this country concur in summer, not only to relax the solids, but to dispose the humours to putrefaction; and as the combination of heat and impure moisture is the great cause of the speedy corruption of animal substances, so it is observed in every place to produce remitting and intermitting fever.”—See Pringle’s Observations on Diseases of the army, pp. 2, 3, 4.