The text on which the book is based is expressed in the title The Dyeing of Woollen Fabrics, and in enlarging upon it the author has endeavoured to describe clearly and in some detail the various processes and operations generally, pointing out the principles involved and illustrating these by numerous recipes, showing the applications of a great variety of dyes in the production of the one thousand and one tints and shades the wool dyer is called upon to produce on the fabrics with which he is working. In pursuance of this plan nothing is said of the composition and properties of the various dyes, mordants, chemicals, etc., which are used. This is information every wool dyer should possess, but the author believes it is better dealt with in books devoted to Chemistry proper.
ether with some fats which are incapable of saponification.
The amount of yolk present upon different samples of wool varies greatly, the finer varieties containing, as a rule, a larger proportion than the coarser, and less valuable sorts.
The variation in the relative amount of pure fibres and yolk is (p. 007) well shown in the following analyses which, however, do not by any means represent extreme cases.
ANALYSES OF RAW MERINO WOOL. DRIED AT 100° C.
No. 1. No. 2. Moisture 6·26 10·4 Yolk 47·30 27·0 Pure Wool 30·31 59·5 Dirt 11·13 3·1 ------ ------ 100·00 100·00
Yolk consists very largely of two complex substances which have been termed wool perspiration and wool fat. The former is composed of the potash salts of fatty acids, principally oleic and stearic acids; the latter of the neutral carbohydrate, cholesterine, with other similar bodies. The wool perspiration may be removed by a simple washin