We lay stress on the use of soured milk or other cultures of the Bulgarian bacillus by people in health as a probable preventive of disease and a possible agent in the lengthening of life, but it may be of interest to give a short account of its use by medical men in the treatment of various ailments. An English authority on the subject, Dr. Herschell, states that the symptoms of the poisoning of the system by the toxic substances produced by injurious bacteria in the large intestine may include headaches, misery and depression of spirits, drowsiness and stupor, giddiness, dimness of sight and dizziness, fatigue without obvious cause, both of the muscles and brain, fear, panic, and nervousness, disagreeable sensations in the limbs or face, such as numbness, tingling, or prickling, crawling sensation of weight or of heat or cold, dyspepsia of the sort where there is a deficiency of hydrochloric acid and pepsin in the gastric juice, accompanied by flabbiness and loss of power in the muscles of the stomach, and characterised by flatulence, nausea, loss of appetite, with discomfort and weight after food, furred tongue, emaciation, earthy colour of the skin, offensive perspiration and the other signs of biliousness, enlargement of the liver, and anæmia. These symptoms may have other causes, and when one or several of them are present a chemical and physical examination of the urine and fæces is necessary to prove that they have resulted from auto-intoxication. When this is shown the soured milk treatment is indicated, and many striking cures are detailed as witnesses to its efficacy. The liver and kidneys are the natural guardians of the body against the toxines we are speaking of, and frequently they are over-strained; the soured milk treatment greatly lightens their load. In malignant disease of the stomach, soured milk will frequently be retained when all other foods are rejected. In cases of neurasthenia and gout it has also proved of value, and in the "run-down" condition which is so common in middle life. Chronic diarrhœa and certain forms of constipation have in numerous instances yielded to the treatment, the whey culture being usually found the most suitable. Then, in some forms of anæmia, the lactic acid cultures have proved most successful, and, as a means of rendering the gastro-intestinal track aseptic previous to operations, they have proved of considerable value. If all this has been accomplished in a year or two, what may not we look forward to in the future when more extended use and experiment shall have more fully exhausted the possibilities of the cure? But if we follow the example of the different nations who have so long used soured milk as a regular article of diet, does it not seem probable that we may eliminate some, at least, of the causes of ill-health that call for the intervention of the doctor?