Although it has been rather dogmatically stated (vide supra) that every one who reaches old age has arteriosclerosis, it must not be inferred that absolutely no exceptions to this rule are found. Cases are known where persons of ninety years even had soft arteries, and we have seen persons of eighty whose arteries could not be palpated. When infants and children are seen with considerable sclerosis, it proves that, after all, it is the quality of the tissue even more than the wear and tear, that is the determining factor in the production of arteriosclerosis. It would be well if those who can not bring healthy progeny into the world were to leave this duty to those who can. In general the treatment of arteriosclerosis is prophylactic and symptomatic. In the preceding chapter I had something to say about prophylaxis in general; I must again refer to it in detail. Arteriosclerosis is essentially a chronic progressive disease, and the secret of success in the management of it is not to treat the disease or the stage of the disease, but to treat the patient who has the disease. To infer the stage of the disease from the feeling of the sclerosed artery, may lead to serious mistakes. Persons with calcified arteries may be perfectly comfortable, while those with only moderate thickening may have many severe symptoms. The keynote is individualization. It is manifestly absurd to treat the laboring man with his arteriosclerosis as one would treat the successful financier. The habits, mode of life, every detail, should be studied in every patient if we expect to gain the greatest measure of success in the treatment. One may treat fifty patients who have typhoid fever by a routine method and all may recover. Individualizing, while of great value in the treatment of acute diseases, yet is not absolutely essential in order that good results may be obtained. Far different is it when treating a disease like arteriosclerosis. One who relies on textbook knowledge will find himself at a loss to know what to do. Textbooks can only outline, in the briefest manner, the average case, and no one ever sees the average book case. At the bedside with the patients is the place to learn therapeutics as well as diagnosis. All that can be hoped for in outlining the treatment of arteriosclerosis is to lay down a few principles. The tact, the intuition, the subtle something that makes the successful therapeutist, can not be learned from books. So the man who treats cases by rule of thumb is a failure from the beginning. There are certain general principles that will be our sheet anchors at all times and for all cases. The art of varying the application of these fundamentals to suit the individual case, is not to be culled from printed words. =Hygienic Treatment=