Hence it is evident that, for hides dried at low temperatures, short soaking in fresh and cold water is sufficient, and, except in warm weather, there would be little danger of putrefaction. With harder drying, longer time is required, and more vigorous measures may be necessary. A well-known tanner recommended a brine of 30°-35° barkometer (sp. gr. 1·035, or about 5 per cent. of NaCl). This has a double action, not only preserving from putrefaction, but dissolving a portion of the hide-substance in the form of coriin, which is undoubtedly a loss to the tanner, though it is questionable if there is any process which will soften overdried hides without loss of weight; since even prolonged soaking in cold water at a temperature which is too low to allow of putrefaction taking place will dissolve a serious amount of hide-substance. Chlorides, however, do not seem well adapted for the purpose in view, from their weak antiseptic power and tendency to prevent swelling. To prevent this Jackson Schulz advised the use of water at 80° F. for soaking during the winter months. Water containing a small quantity (0·1 per cent.) of carbolic acid has been recommended for the purpose, and will prevent putrefaction, while it has no solvent power on the hide, but, on the contrary, tends to coagulate and render insoluble albuminous matters. Borax has been proposed for the same purpose, and, in 1 per cent. solution, certainly prevents putrefaction, and has considerable softening power, but is far too costly. Other methods of chemical softening are described on p. 115.