Excerpt from Tests of Iowa Limes Slaking Is a physical evidence of the hydration of lime, but it is not to be understood that Slaking is a necessary result of such chemical action. The two processes are really distinct. The exposure of caustic lime to a moist atmosphere occasions slow hydration, accompanied by crumbling to a powder. Along with this change occurs an increase in volume of about one and three-quarters times that of the original lime. Such lime is air-slaked and is largely changed to the hydroxide ca(oh) If this lime be exposed to water, it will further increase in vol ume, but the paste resulting will be Sharp and sandy in texture, and of much less value for mortar purposes than freshly slaked lime. In this case a portion of the oao has no doubt combined with the 002 of the air, so that air slaked lime is. Actually a mixture of lime hydrate and car bonate. It is possible also to bring about the complete hydration of lime by steam at temperatures above boil ing, without any change of volume or any sign of crumbling. Slaking may, therefore, be defined as the hydration of calcium oxide, quicklime, accompanied by an increase in temperature and volume. The increase in temperature is caused by the combination of the lime and water. It is an exothermic reaction, one in which heat is evolved. Whether or not this heat becomes evident depends on the vigor and rapidity of the reaction. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.