An Bjfqy on Bleaching i 305 



Far from being a matter of indifference in a large eft ablifh- 

 ment. To this we may add, that in the application of thefe 

 deterfive liauors the cloth muft be boiled at leaft feven hours 

 in the alkaline ley, while the folution of fulphnret of lime 

 requires only half an hour; and even if we fuppofe that pot- 

 am mail continue to be ufed along with the fulphuret of lime, 

 as is the cafe at prefent in Ireland, the faving will be (lill 

 very coniiderable. 



Bleaching with Steam, 



The different proceffes which we have hitherto defcribed 

 form almoft an hiiiorical abridgement of the art of bleaching. 

 We have followed the progrefs of the human mind 5 and, 

 indeed, a plain account, of the various proceffes and different 

 kinds of apparatus fufficiently (hows what fervice has been 

 rendered to this important art by modern chemiftry. 



But it flill remains to make known a new method, for 

 which we are indebted to Chaptal. This refpectable chemift 

 published, about two years ago, a notice reflecting the method 

 of bleaching by fteani ; a procefs brought to us from the Le- 

 vant fome time after the introduction of that for dyeing 

 Adrianople red, and which is now ufed in the fouth of 

 France under the name of blanchiment a la fum»e. Till the 

 period when Chaptal was fo ditinterefted as to difclofe it tor 

 the public, it was a fecret the knowledge of which was con- 

 fined to a certain number of manufacturers. It was em- 

 ployed only for bleaching cotton and cotton thread after the 

 manner of the orientals; but C. Chaptal forefaw, with his 

 ufual acutenefs, the poffibility of applying this method to 

 bleaching linen and hemp thread; ana he invited manufac- 

 turers to adopt this procefs, in order to improve it and extend 

 its ufe. 



Chaptal's invitation excited feveral manufacturers both in 

 France and in foreign countries. Almofl: at the fame time, 

 the effects of the new method of bleaching were tried in the 

 neighbourhood of Paris and in Ireland: the apparatus feen 

 at the cotton manufactory of C. Bawens, at Bons-Hommes, 

 near Paffy, gives the molt aftoniilring refults. It can bleach 

 from two to three thoufand yards of cotton cloth per day, at 

 a price fo moderate, urnX with fuch facility, that no other 

 procefs can be compared to it. The firft experiment which 

 he tried was made on fifteen hundred yards of cloth defined 

 for beine; printed : it exhibited no blemifh or (hade, but was 

 all equally white. 



His apparatus has a perfect refemblance to that defcribed 

 by Chaptal, and which may be employed exceedingly well 



Vol. X. U alio 



