Not many years ago we drank freely of such water as was at hand, without realization of danger from bacteria or disease germs, looking on epidemics of typhoid fever perhaps as a visitation of Divine Providence, in punishment of our many sins and to be borne meekly and with resignation. But all this has changed through the researches of bacteriologists and chemists; scientific facts of the utmost importance have been clearly established; a classification of water-borne diseases has been adopted, and we realize fully that diseases of this order can be kept from our doors by proper precautions applied to our water supply. To-day, epidemics of typhoid fever are traceable solely to the ignorance or carelessness of the individual or of the commonwealth, and the exemption which we of the present generation have from this class of diseases is directly due to the application of precautionary measures based on the information furnished by scientific investigation. It is proper for us to use caution in the acceptance of new ideas, but not that form of caution which refuses change on the ground that what has been is sufficiently good for the present and the future. The point of view is ever changing with advance of knowledge, and it is not profitable to exclude opportunities for improvement in personal hygiene and general good health, any more than in other matters that affect the prosperity of the individual or the community. Dietary habits should be brought into conformity with the true needs of the body. Excessive consumption of proteid food, especially, should be avoided on the ground that it is not only unnecessary and wasteful, but is liable to bring penalties of its own, most undesirable and wholly uncalled for. We may, perhaps, accept these statements at their full value, and yet have a shadow of doubt in our minds as to whether, after all, dietary customs do not harmonize sufficiently at least with true nutritive requirements. All the data that we have presented in the preceding chapters, however, have seemingly given a positive answer to such doubts, and indicate quite clearly that the results of scientific study are opposed to the prevailing dietary standards, especially as regards proteid food. As the celebrated physiologist Bunge has expressed it, “The necessity for a daily consumption of 100 grams of proteid is incomprehensible, so long as we do not know of any function of the body in the performance of which the chemical potential energies of the destroyed proteid are used up.”