| Skin with hair | 1·450 |
| " depilated with lime | 1·425 |
| " depilated with sodium sulphide | 1·441 |
but does not give details how these figures were obtained, and if corrected for ash and fat.
The density of limed and puered sheepskin, determined by drying the skin over sulphuric acid until the weight was constant, then determining the volume in petroleum, gave the following results:—
| Limed skin | 1·2335 | |
| Puered " | 1·2590 | I. |
By determining the volume of the wet skin in the volumenometer, and the per cent. of water on drying the skin, the calculated densities were—
| Limed skin | 1·438 | |
| Puered " | 1·300 | II. |
Correcting for ash and fat, the dry ash-free skins had the densities—
| Limed skin | 1·397 | |
| Puered " | 1·335 | III. |
The density of the wet limed skin was 1·063, but the density calculated from the results (I.) above is 1·0475; from this, it is evident the fibres of the swollen limed skin undergo compression on swelling, or that the water contained in them is in a state of compression, in the same way as gelatin swollen with water occupies a less volume than the sum of the volumes of gelatin and water. Lüdeking[50] found for 10 per cent. gelatin jelly δ = 1·069; δ calculated was 1·041. He attributed the whole of the compression to the water, so that 1 c.c. of water in a 10 per cent. gelatin jelly occupied a volume of 0·96069 c.c. See also par. 4 p. [68].