However irrefragably these numerous facts and authorities establish the assertion of the prevalence of but one powerful epidemic at a time, the proposition will receive fresh support, from attending to the effects of two impressions of unequal force made upon the system at the same time: only one of them is felt; hence the gout is said to cure all other diseases. By its superior pain it destroys sensations of a less painful nature. The small-pox and measles have sometimes existed together in the body; but this has, I believe, seldom occurred, where one of them has not been the predominating disease[45]. In this respect, this combination of epidemics only conforms to the general law which has been mentioned. [45] Hunter on the Venereal Disease, introduction, p. 3. I beg pardon for the length of this digression. I did not introduce it to expose the mistakes of those physicians, who found as many diseases in our city as the yellow fever had symptoms, but to vindicate myself from the charge of innovation, in having uniformly and unequivocally asserted, after the first week in September, that the yellow fever was the only febrile disease which prevailed in the city. Science has much to deplore from the multiplication of diseases. It is as repugnant to truth in medicine, as polytheism is to truth in religion. The physician who considers every different affection of the different systems in the body, or every affection of different parts of the same system, as distinct diseases, when they arise from one cause, resembles the Indian or African savage, who considers water, dew, ice, frost, and snow, as distinct essences; while the physician who considers the morbid affections of every part of the body (however diversified they may be in their form or degrees) as derived from one cause, resembles the philosopher who considers dew, ice, frost, and snow, as different modifications of water, and as derived simply from the absence of heat. Humanity has likewise much to deplore from this paganism in medicine. The sword will probably be sheathed for ever, as an instrument of death, before physicians will cease to add to the mortality of mankind, by prescribing for the names of diseases. The facts I have delivered upon this subject will admit of a very important application to the cure, not only of the yellow fever, but of all other acute and dangerous epidemics. I shall hereafter assign a final cause for the law of epidemics which has been mentioned, which will discover a union of the goodness of the Supreme Being with one of the greatest calamities of human life.