It can scarcely be doubted that many Specific diseases are caused by the introduction into the system of specific germs; but how many diseases are there which come strictly under the denomination of specific? Is diphtheria, for instance, a strictly specific disease, produced by the introduction into the system of specific disease germs, and which produce this disease, and no other? It is doubtful if this question can be con fidently answered in the affirmative. Diphtheria is rather a protean disease; assumes various forms, has variable symptoms, runs no specific course, and has no definite, or anything like a definite, period of incubation, although it is attended by the develop ment of fungoid organisms. That it is contagious there is scarcely a doubt, and this may be regaided as strong evidence of the specificity of the contagion. The question is very difficult, and it is probable that the most which can now be said is that diphtheria is the product of a virulent poison, which may be in the form of a gas, or a vapor, sometimes introduced from the sewer, sometimes from the cess pool, sometimes gener• ated by the garbage pile or the compost heap of the farm-yard, sometimes taken from the well, whither, dissolved in water, it has drained through a porous soil from the adjoining privy or cess pool. Whether the organisms that sewer and cesspool gases and vapors arc known to carry are the peculiar disease germs, has not been decided, although it is exceedingly probable that the inflammatory lesionswhich often take place in this disease, and Which contain bacteria, are caused by the plugging up of the capil lanes, as in anthrax, It is quite possible that in both these there are two elements, that of the growing organism, mechanically interfering wit me circulation, and that of a separate poison, which is the peculiar malignant principle, but which may also be the product of the growth of the organism, or may precede it, and prepare the way for its development. While these questions have not been settled, there are many
facts in regard to the propagation of many diseases which are well known, and of the greatest practical value. • It is known that the progress of diphtheria may be arrested by the use of a solution of carbolic acid, and that, in general, disinfectant remedies and a blood-enriching and supporting treatment is beneficial. It is also known that negligence, which ought to be regarded as criminal, on the part of public officers, is one of the chief causes of the bad sanitary conditions by which the disease is propagated. When the majority of the community recognize the fact that sewers should be so constructed and so connected with dwellings as not to be the injectors of poisonous vapors and gases; and when they are also fully convinced of the great impropriety of collecting drinking water from pasture fields, swamps, and ditches, which not only contain many aninpls and receive and transmit to the reservoir much of their excreta, but also receive the drainage of farm-yards and hog pens; and when they are also convinced of the danger of collecting it from streams which receive the sewerage of villages, the remedy for these evils will certainly be forthcoming, especially when neighboring sections of country are of such formation as to afford facilities for the excavation of wells and channels by means of which pure, filtered water from vast gravel beds can be obtained in great quantities.