A perfectly safe and pleasant substitute for chloroform, ether, and all other anaesthetics. Discovered by Dr. U.K. Mao, April, 1884, and since administered by him and others in over 106,000 cases successfully. Compounded from nervines which impart oxygen to sustain life, (Nitrous oxide gas, as administered, is destitute of this and tends to produce convulsions and suffocation). The youngest child, the most sensitive lady, and those having heart disease and lung complaint, inhale this vapor with impunity. It stimulates the circulation and builds up the tissues. Recommended in midwifery and all cases of nervous prostration. Physicians, surgeons, dentists and private families supplied. For further information, pamphlets, testimonials, etc., apply to Dr. U.K. MAYO, Dentist, 378 Tremont street, Boston, Mass.

BOSTON, August 15, 1883.

This certifies that I removed in the back of Mr. J.D. Moore a tumor weighing two pounds and three-quarters. The time occupied was twenty-two minutes. The patient was insensible during the whole operation, and came out from the influence of the anaesthetic speedily and perfectly, without nausea or any ill effects. The agent used was prepared by Dr. U.K. Mayo, the dentist, a new discovery of his own. I consider this anaesthetic the safest the world has yet seen.

WM. H. THORNDIKE, M.D., 92 Boylston, Street.