IN a communication to NATURE on the eradication of slugs, which was the subject of a note in these columns on July 16 (p. 90), Mr. Walker Van Riper, 771 South High Street, Denver, Colorado, contributes another method of control based on his own experience. A generous distribution of a solution of ammonium sulphide (1 part in 30 parts of water) killed nearly all the slugs present in his garden in a single application, and no injury to any of the plants was observed. Although no special apparatus is essential, the following method for distribution is suggested. A water suction pump (ejector) is attached to the garden tap, and hose piping leads from the suction opening into the barrel containing ammonium sulphide solution. The distributing hose is connected to the other end of the filter pump. On turning on the tap, the solution is drawn off from the barrel, mixed with water from the tap, and forced through the distributing hose. Calculation and trial are of course needed to determine the strength of ammonium sulphide solution in the barrel in order to yield 1 part in 30 in the distributing hose. Mr. Van Riper would welcome the reports of other experience in the use of this method for slug eradication.