Hence it may be argued, that if a malaria, generated any where and conveyed by the winds, can be transported to a distance of three miles, as has been proved, there is no reason why it should not travel much farther, or to any distance that can be assumed: and if this be true of a clear wind, the case of a fog is even a much stronger one; since there is little reason to doubt that the individual parts of such fog, in any assumed mass, will retain their relative places to each other, as perfectly after a journey of any given number of miles, as they did at the point of production; and if a portion of malaria has been united to a portion of fog, in the marsh which produced both, or whence both have come, there is every apparent reason why it should be found in that same portion at any farther or assumed distance, because there is no cause for either its dispersion or its decomposition. A fog is a cloud, simply; and it is notorious that a single [p048] cloud, and often of very small dimensions, will remain at rest in the atmosphere, or travel very many miles without the loss of its integrity; however we may imagine it assailed by the various meteorological causes of destruction, as well as by mechanical violence. This in itself proves the consistency with which a current of wind preserves the relative positions of its integral parts; because it is plain that a disturbance among these must disturb or destroy the cloud which, in reality, forms a portion of that current, as a gaseous body: and since that cloud is a mist, since it might have been the very evening mist embodying a malaria, and since it is its real vehicle and repository, it is plain that had it, or any individual cloud, contained such a portion of malaria, it must have had the power of transmitting that, and would actually have transported it to any distance to which itself might travel. Thus, it is evident, may a fog, generated in Holland, carry without difficulty to the limits of its range, or to the coast of England, that malaria which became entangled with it at its birth-place or in its passage; and thus, I have little doubt, is the fact of those agues explained, and this transportation to such distances established. I cannot, at least, conceive any demonstration as to facts of this nature more convincing, nor anything wanting to the proof; while I may proceed to make some remarks on the east wind, and on fogs, simply, because they concern this question.