Some of these neutral salts appear to be absorbed by the skin during the course of the bating, for, on examining pieces of the same skin at frequent intervals during the operation, and determining the ash, it was found that a minimum point for ash content was reached in about ten minutes, after which the ash actually increased. The results are shown in the following table, and also graphically by the curves, Fig. 7--in which A is a “grain” previously washed as free from lime as possible; B, an unwashed “roan.” The effect of the absorption of inorganic matter is very noticeable in both cases. A part of the effect only is apparent since a certain amount of skin substance passed into solution. VARIATION OF ASH PERCENTAGE DURING PUERING. -----------------+-------------------------------- -- | Ash, per cent. on Dried Skin -----------------+----------------+--------------- Time of Puering | Washed Delimed | Limed Roan (B) in Minutes | Grain (A) | -----------------+----------------+--------------- 0 | 2·88 | 7·03 5 | 2·91 | -- 10 | 3·20 | 3·54 15 | 4·80 | -- 20 | 4·08 | 4·24 25 | 4·29 | -- 30 | 4·85 | 5·19 35 | 4·59 | -- 40 | 4·70 | 5·45 45 | 4·60 | -- 50 | 4·45 | 5·67 55 | 4·42 | -- 60 | -- | 5·00 -----------------+----------------+--------------- The following analyses give the amount of lime in solution before and after the bating of the skins, in grams per litre of filtered puer liquor:-- ---+-----------------+------------+-----------+--------------- No.| Bate |Before Goods|After Goods|Increase of CaO ---+-----------------+------------+-----------+--------------- 1 |Fresh puer | 0·108 | 0·62 | 0·512 2 | " " | 0·34 | 0·72 | 0·38 3 | " " | 0·20 | 0·52 | 0·32 4 | " " | 0·19 | 0·49 | 0·30 5 |Old puer | 0·54 | 0·84 | 0·30 6 |{Old puer, goods}| 0·98 | 1·38 | 0·40 |{not washed. }| | | 7 |{French puer }| 0·308 | 0·548 | 0·24 |{shop. }| | | ---+-----------------+------------+-----------+---------------