164 CHEMISTRY. 



of bleaching was very tedious and uncertain, but chlorine 

 bleaching is both an expeditious and certain process. Pro- 

 fessor Pepper, an English author, thus remarks on the bene- 

 fits which the discovery of this process has conferred upon 

 English manufacturers : " All our linen used formerly to be 

 sent to Holland, where they had acquired great dexterity 

 in the ancient mode of bleaching, viz., by exposure of the 

 fabric to atmospheric air, or the action of the damps and 

 dews, assisted greatly by the agency of light. Some idea 

 may be formed of the present value of chlorine when it is 

 stated that the linen goods were retained by the Dutch 

 bleachers for nine months ; and if the spring and summer 

 happened to be favorable, the operation was well conduct- 

 ed ; on the other hand, if cold and wet, the goods might 

 be more or less injured by continual exposure to unfavor- 

 able atmospheric changes. At the present time as much 

 bleaching can be done in nine weeks as might formerly have 

 been conducted in the same number of months ; and the 

 whole of the process of chlorine bleaching is carried on inde- 

 pendent of external atmospheric caprices; while the money 

 paid for the process no longer passes to Holland, but re- 

 mains in the hands of our own diligent bleachers and man- 

 ufacturers." Quite as great is the usefulness of chlorine 

 bleaching in the art of paper-making in the preparation of 

 its material. A most valuable present, then, did the Swed- 

 ish chemist Scheele make to the arts when he discovered 

 chlorine and its application in bleaching. 



219. Difference between Chlorine Bleaching and Sulphur 

 Bleaching. In chlorine bleaching the coloring matter is actually de- 

 stroyed burned up that is, its elements are dispersed in new combinations. 

 But in sulphur bleaching, as you will learn, the coloring matter remains. 

 It is only changed, not dispersed, and therefore it can be restored as before 

 by certain chemical actions. Chlorine bleaching is inapplicable to straw, 

 because for some reason it imparts a brown tinge to the material. There- 

 fore for straw goods sulphur bleaching continues to be used. 



