" process, injury to fur in, 17

Sericin, 7

Shellac, 62
" colouring of, 103
" rosin in, detection of, 63
" solvents for, 63
_See also_ Lac.

Silk fibre, action of acids on, 7
" " " of alkaline solution of, copper and glycerin on, 7
" " " of alkalis on, 7
" " " of basic zinc chloride on, 7
" " bleaching of, 7
" " composition of, 7
" " structure of, 6
" " ungumming of, 7
" glue, 7
" gum, 7

Soap, 60
" alkali in, detection of, 61
" oleic acid, 101
" palm oil, 101
" water in, determination of, 60

Soda. _See_ Alkali.

Solution, 36
" precipitation of insoluble compounds from, 38

Specific gravity, 30

Spectra of coloured substances 112

Spectroscope, 111

Spectrum, 108
" absorption, 113
" continuous, 111
" discontinuous or line, 111

Spirits of salt. _See_ Hydrochloric acid.

Starch, 4

Steam, 31
" latent heat of, 34

Stiffening mixture, 63
" process, 64
" " Cheetham's, 66
" " Continental, 66
" " effect of, in dyeing 65, 103

Suint. _See_ Wool grease.

Sulphur in wool, fur, and hair, reagents for detection of, 26

Sulphuric acid, manufacture of, 50
" " " by contact process, 52
" " " by lead chamber process, 51

Sumach, 99

Tannins, 99

Tincal, 59

Tiza, 59

Toluene, 90

Toluidine, 91

Turmeric, 80, 83, 85, 87

Twaddell hydrometer degrees, 31

Ultramarine blue, 81

Ultramarine green, 81
" rose-coloured, 81

Valency, 71

Vegetable fibres. _See_ Fibres.

Veneering process, 66

Vermilline scarlet, 91

Vitriol. _See_ Sulphuric acid.

Water, 29
" boiling of 31
" boiling-point of, effect of dissolved salts on 36
" boiling-point of, effect of increase of pressure on, 35
" chlorides in, detection of, 47
" composition of, 29
" contamination of, by factories, 45
" copper in, detection of, 46
" decomposition of, by potassium, 25, 30
" filtration of, 47
" hard, 41, 42
" " Clark's soap test for, 43
" " softening of, 41
" " waste of soap by, 43
" hardness, temporary and permanent, of, 42
" impurities in, 42
" " effect of, in dyeing, 42
" " ferruginous, 44
" iron in, detection of, 46
"