On the action of slightly alkaline waters on iron

Abstract

IT has been the practice of one of us during the last ten or fifteen years, when examining waters intended for use in steam boilers, to make a trial experiment with the water, using a slipof thin steel 4 inches long by 1 inch wide.A hundred C.C. of the water are placed in a boiling-tube, the steel slip-brightly polished with emery, not cleaned by chemical means-inserted, and the whole kept at 100" C. (or as near to that temperature as a water-bath will bring it) for twentyfour hours, after which the nature of the action is examined and its extent measured. I n most cases a similar experiment is made at the air temperature. At the end of the time the deposit, if any, is washed off the surface of the metal, and the total amount of iron in solution and in suspension in the water is estimated.Of course the test is a very imperfect one. I t does not reproduce in any way the making boilers, and the steel with which most of the experiments in connection with the paper were made, act practically alike. Even the 1 L skin " does not prevent the local action in any way, and the action goes on at the same rate, or even more energetically, therefore the nature of the metal is no bar to the action,