It is difficult to give any definite marks of sufficient bating other than the soft and fallen feel of the hides, which is easily recognised by a practised hand. One of the earliest signs of commencing overbating is the occurrence of bluish patches, or a bluish tinge somewhat similar to an iron-stain, which, if slight, generally disappears in a few days after the hides are taken into the liquors. Hen- and pigeon-dung is probably best kept air-dried, though, if very wet, or for convenience for immediate use, it may be kept in paste like dog-dung. Dog-dung should never be allowed to lie exposed to the air, or it putrefies and turns black, the bating ingredients are destroyed, and it will not puer the goods which turn black and putrid without softening. Dung should, therefore, be mixed to a paste with water and kept in tanks, so as to be but little exposed to the air, when it will retain its puering properties for a long time unaffected. Fresh dung should be allowed to ferment for at least a week before use. No accurate statement can be made as to the quantities required. Eitner states that 1-1¹⁄₂ pails of dung-paste (say 14-20 litres) is sufficient for 200 medium to large lamb-skins for glove-kid. It should be sufficient to make the water quite turbid, but not thick or soupy. For lamb-skins a temperature of 18°-20° C. is suitable, which may be raised in very cold weather to 25° C., to allow for cooling. The time required is from two hours for the thinnest slink skins, to 12-14 hours for strong ones. It is well to use wooden, and not iron, utensils for handling the dung, and it should be strained through a coarse cloth after diluting with water. As has been remarked, it is not desirable to keep the skins in constant motion in the puer; they should be stirred or paddled for the first 20-30 minutes, and then for 10 minutes every hour for five or six hours, after which they can be allowed to lie for a longer period without injury. Puering is sufficient when the skins feel quite soft and flaccid, hanging in folds in any direction and allowing the flesh to be scraped off with the finger-nail.