It was valued chiefly on account of its brilliancy of tone and its inertness in opposition to sunlight, oil, and slaked lime (in fresco-painting).
Clay-pipes may also give rise to cancer of lips in males in England, while cancer of the mouth of both sexes is common in India where chewing a mixture of betel leaves, areca-nut, tobacco and slaked lime is the usual practice.
When recommendations are made about liming land it is necessary to indicate more precisely than is usually done which of the three classes of material named above - chalk, quicklime or slaked lime - is intended.
The usual proportions are three of slag to one of slaked lime by weight.
The product may then be regarded as a cement of the Portland class mixed with slaked lime.