1895 Journal of the American Medical Association (JAMA)  
It is a fact of familiar observation and comment that irregular cases of malarial disorder are occasionally met with at all seasons of the year and in all localities. It is equally well known that the conditions existing in large cities are inimical to the production of the malarial poison. The busiest metropolitan physician sees very few examples of frank periodical malarial fever that unquestionably originated in paved and sewered portions of his city. The rare cases that do occur are
more » ... o occur are accounted for upon the assumption of "limited foci " of infection. If an excavation for building purposes is found in the neighborhood, no matter what the season of the year, it is readily assumed that the upturning of the soil is the cause of the patient's sickness. Or, if the individual has been out of the city, at any time within a period of a year or two, it is taken for granted with equal promptitude and with equal lack of knowledge of the truth, that he received the infection at that time, and that it has been sleeping or " latent" in his body ever since ; and if he actually visited a region known to be malarious, even though it were several years before, the discovery of the fact is regarded as having almost the force of a demonstration of the exact time and place of intoxication. And, if no recent excavation can be discovered and no absence from the city has occurred, it is nevertheless unyieldingly maintained that some subtle emanation from the soil, somewhere, must be held responsible for the result. In considering this problem it is well to include the questions of season, climate and locality. Contemplate the climate of Chicago between November and March when the earth is frozen to a depth of a foot or more, a good part of the time, and also covered with frozen snow-to say nothing of macadamized pavement; when the temperature has been below zero for a month and below the freezing point for several months; when building operations have been arrested and a recent excavation can not be found anywhere; and then try to account for the malarial affections that prevail on the finest avenues and boulevards of that city during and between the months named, by assuming that there has been some subtle morbific emanation from the soil! The country surrounding the head of Lake Michigan was intensely miasmatic before it became densely populated and comparatively well drained; and the environs of Chicago are miasmatic still. Modern treatises say that the presence of malarial disorders in the region of the Great Lakes is not extensive, but is limited mainly to the vicinity of Lake St. Clair and the southern shore of Lake Erie. I have believed and maintained for many years that there were no such disorders in Chicago, that originated in finished portions of the city, except here and there a chance case from fresh upturnings of the soil.
doi:10.1001/jama.1895.02430200001001 fatcat:45c3mf3vojhxbgraldq74jc4pq