This section is from "Scientific American Supplement Volumes 275, 286, 288, 299, 303, 312, 315, 324, 344 and 358". Also available from Amazon: Scientific American Reference Book.
As an instance of this nearer home, I may mention that last winter at Cannes, in the south of France, some extensive works adjacent to the town were begun which required a large quantity of earth to be moved. The weather was exceptionally warm; an outbreak of fever occurred among the workmen, of whom fifteen died. This fever was attributed to the turning up of the soil.
If a strong solution of quinine be let fall in the water containing these organisms they at once die; the efficacy of quinine as a preventive of this form of fever would therefore not be inconsistent with this theory. Upon this subject the President called attention to the view of Sir Joseph Fayrer, who acknowledged the importance of the discovery if it should be confirmed, but considered that there was a possibility that the results attributed to these influences might, to some extent, be due to disturbance of the system in a body predisposed to be deranged by peculiarity of constitution, climatic or other influence of the nature of which we are ignorant, though it is conceivable by analogy.
The marvelous facility of reproduction of various germs, as shown by Pasteur in the case of chicken cholera, was dwelt upon; and the President said that it would be a wonder how any higher form of life could exist subject to the possibility of invasion by such countless hosts of occult enemies were it not seen that the science of the prevention of disease advanced quite as rapidly as our knowledge of the causes. Holding that the attitude of the sanitarian, in regard to the germ theory of diseases, as applied to all diseases of the zymotic class, must be one of reserve, yet, he said, even if the views of those who are prepared to accept the germ theory of disease to its fullest extent were shown to be true, it seems to be certain that if the invasion of these occult enemies present in the air is undertaken in insufficient force, or upon an animal in sufficiently robust health, they are refused a foothold and expelled; or, if they have secured a lodgment in the tissues, they, so to speak, may be laid hold of, and absorbed or digested by them.
In corroboration of this view, Professor Koch and others state that the minor organisms of tubercular disease do not occur in the tissues of healthy bodies, and that when introduced into the living body their propagation and increase is greatly favored by a low state of the general health. The President held that for the present sanitary procedure was independent of these theories on the germ origin in particular of zymotic disease; but gave the facts as worthy of consideration, as indicating points for the direction of those who aimed at preventing disease.
The President dealt with the important subject of isolation in the cases of contagious zymotic diseases, and then, proceeding to discuss the subject of epidemic diseases, said: Notwithstanding the numerous experiments and the great efforts which have been made in recent times to endeavor to trace out the origin of disease, the sanitarian has not yet been able to lift up the veil which conceals the causes connected with the occurrence of epidemic diseases. These diseases come in recurring periods, sometimes at longer, sometimes at shorter intervals. Animals, as well as the human race, are similarly affected by these diseases of periodical recurrence; but why they prevail more in one year than in another we are entirely ignorant. They appear to be subject to certain aerial or climatic conditions.
Cholera affords an illustration of this. There is a part of India, low-lying, water-logged, near the mouth of the Ganges, where cholera may be said to be endemic. In certain years, but why we know not, it spreads out of this district, and moves westward over the country; the people are sedentary, and seldom leave home, but the cholera travels on. At last it arrives on the borders of the desert, where there are no people, and no intercourse, no alvine secretions, and no sewers, yet the statistician sitting in Calcutta can tell almost the day on which the epidemic influence will have crossed the desert. But it exercises discrimination in its attacks, It will visit one town or village and leave many others in the vicinity untouched. Similarly it will attack one house and leave another. But it has been generally found that the attacked house or village held out special invitation from its insanitary condition. The same houses or the same localities will be revisited in recurring epidemics, because the conditions remain the same; remove those conditions, and at the next recurrence the locality will escape. At Malta it was found that the same localities and houses which yielded the majority of plague deaths there in 1813 yielded the majority of the deaths in the cholera epidemics of 1839 and 1867, and that in the intervals the same localities yielded the majority of cases of small-pox, fever, and of an anthrax, a very special eruptive epidemic attended by carbuncles. Hence, while we are unable either to account for the cause or to prevent the periodic recurrence of epidemics, the sanitarian has learnt that it is possible to mitigate the severity of the visit; and that, whether these evils arise from the occult causes to which I have alluded, or from other causes, pure air and pure water afford almost absolute safeguards against most forms of zymotic diseases.
In speaking of the pure-water question, he remarked: Although there are many theories as to how far water which has once been contaminated by sewage may again after a time become fit to drink, I am disposed to think that there has never been a well-proved case of an outbreak of disease resulting from the use of drinking water where the chemist would not unhesitatingly on analysis have condemned the water as an impure source; and it appears probable that, whatever may be the actual causes of certain diseases--i.e., whether germs or chemical poisons, the materies morbi which finds its way into the river at the sewage outfall is destroyed, together with the organic impurity, after a certain length of flow. He pressed that there should be no further delay in bringing the Act for the Prevention of Pollution of Rivers into operation, and in enforcing the provisions of the Acts. In regard to the pollution of the air, he called attention to the fact that nearly fifty years ago Mr. Edwin Chadwick impressed upon the community the evils which were caused by the impure condition of the air in our towns owing to the retention of refuse around houses. The speaker remarked that the gases, which were the result of putrefaction, were offensive to the smell, and some of them, such as sulphureted hydrogen, when present in undue proportions in the air, would kill persons outright, or when those gases were in smaller proportions in the air breathed by people, there would be a lowered tone of health in the individuals exposed to them. Continued exposure might lead to the development of other conditions, which, in their turn, might lead to disease or death.