Note 9 — Chapter II · THEORIES OF MACCULLOCH.

Rapid changes in the barometric pressure of the atmosphere strongly affect some persons, but the malaise caused does not seem to be of a permanent character. In the spring, in Britain, when north-easterly winds prevail, the amount of skin disease, rheumatism, neuralgia, &c., is sufficiently remarkable, and the blights they cause in plants is a fact known to all. In a work published by Mulder (“Water en Miht,” Amsterdam, p. 181), we find it mentioned that Van Swinden investigated the mutations of atmospheric pressure as a cause of sickness, and arrived at the conclusion that a low pressure was not the cause of sickness and fever. He remarked that although there had been many years in which much sickness prevailed, seemingly connected with hot and dry weather, the barometer had varied but little. Thus, at Haarlem, in the period between 1755 and 1780, the maximum was 30·9, the minimum or lowest, 28·0. The summer of 1779 was extremely hot, and a fever epidemic appeared which continued for three years. It was ascribed to the draining of several polders. Several learned societies made reports on the subject of this fever, but they elicited no new facts. It was generally agreed that the deeper the mud and turf containing vegetable matter were under water, the less was the sickness resulting from the draining. A Mynheer Driessen called public attention to the circumstance that on the coasts of Holland there were many places where animal and vegetable matter had accumulated and was in a state of rottenness or fermentation; and in this state he suggested that being carried inland by strong westerly winds, it might give rise to sickness. It is remarkable, however, that both the influenza and cholera progressed against the prevailing westerly winds.