Koumiss is frequently ordered by physicians for patients who are convalescent an who require an easily digested and nutritious tonic. It is prepared as follows: Heat pure, fresh milk to about 100 degrees, then add to each qt 1 1/2 tablesp sugar, 1 tablesp fresh, lively yeast or a liberal 1/4 cake of fresh compressed yeast, dissolved in 1 tablesp lukewarm water, stir until thoroughly mixed, and then put in pint bottles to within about 2 inches of the top, and cork tightly and tie the corks down securely. Let stand from 10 to 12 hours in a temperature of about 60 to 70 degrees, after which it will be ready for drinking. Keep in a cool place and chill before using. The average dose for an adult is 1 glass, three times a day. Do not prepare too much koumiss at once, as it is not good when it gets old. One qt milk, with the other ingredients, will be about enough for 3 pt bottles, and more than that should not be prepared at one time for only one patient.- [A. G., Mass.