8 | 19.2 |
| 18 deg. | 0 | 0 | 0 | 0 | 0 | 0 | 8.0 | 8.8 | 11.8 | 19.8 |
| 30 deg. | 0 | 0 | 0 | 0 | 0 | 0 | 4.6 | 4.6 | 6.0 | 19.0 |
| 80 deg. | 0 | 0 | 0 | 0 | 0 | 0 | 3.5 | 3.5 | 9.8 | 13.4 |
|_______________|___|____|____|___|____|____|______|______|______|______|
_______________________________________________________________________
| | | | |
| Concentration | | | |
| of lye (NaOH) | 25 deg.B | 30 deg.B | 35 deg.B |
| | | | | | | | | |
| Duration of | | | | | | | | |
| action in | 10 | 30 | 1 | 10 | 30 | 1 | 10 | 30 |
| minutes | | | | | | | | |
| | | | | | | | | |
| Temperatures | Percentage shrinkages (Egyptian yarns) as under:-- |
| as under:-- | | | | | | | | |
| 2 deg. | 19.8 | 21.5 | 22.7 | 22.7 | 22.7 | 24.2 | 24.5 | 24.7 |
| 18 deg. | 20.1 | 21.0 | 21.2 | 22.0 | 22.3 | 23.5 | 23.8 | 24.7 |
| 30 deg. | 19.5 | 19.0 | 18.5 | 19.5 | 19.8 | 20.7 | 21.0 | 21.1 |
| 80 deg. | 13.7 | 14.2 | 15.0 | 15.1 | 15.5 | 15.0 | 15.2 | 15.4 |
|_______________|______|______|______|______|______|______|______|______|

The more important general indications of the above results are--(1) The
mercerisation action commences with a lye of 10 deg.B., and increases with
increased strength of the lye up to a maximum at 35 deg.B. There is,
however, a relatively slight increase of action with the increase of
caustic soda from 30-40 deg.B. (2) For optimum action the temperature should
not exceed 15-20 deg.C. (3) The duration of action is of proportionately
less influence as the concentration of the lye increases. As the maximum
effect is attained the action becomes practically instantaneous, the
only condition affecting it being that of penetration--i.e. actual
contact of cellulose and alkali.

(d) The question as to whether the process of 'mercerisation' involves
chemical as well as physical effects is briefly discussed. The author is
of opinion that, as the degree of lustre obtained varies with the
different varieties of cotton, the different