METHOD OF BLEACHING PAPER. 123 



fpect ; but this expenditure, befides weakening the bleaching 

 liquor, nearly doubled our expence. Though this difference 

 in the price was of little confequence with regard to the ob- 

 ject we then had in view, it is not (b with regard to the 

 common operation upon paper intended for fale. Every 

 means of economy mull then be ufed. Now Citizen Welter 

 found that it is eafy to obviate the inconvenience of the iirhple 

 liquor in the operation. His method confills in no longer 

 agitating the goods or material in an open bath, but to 

 clofe it exactly by means of a cover ; and he agitates it by 

 means of crofs pieces attached to a handle turned on the 

 outfide, 



A rough eflimate of the price of the fimple bleaching Eftimate of 

 liquor prepared by the fulphuric acid, this being the moft c arg $ * 

 economical procefs. 



The receiver is fuppofed to contain 1000 litres of water. 



25 kilograms of oxide of manganefe coft at 



molt - - - 15fr. Oc. 



70 kilograms of muriate of foda - 7fr. Oc. 



25 kilograms of fulphuric acid, at 50 deg. 37 fr. 50c. 



Three days work, principal men - 9fr. Oc. 



Three days , affiftant or labourer 4fr. 50c« 



Fuel, about - ' - - 3fr. 



Wear and tear ... 6n\. 



Our apparatus coft 622 franks, and the car- 

 riage and fixing increafed our expence 

 to 1000 franks, the intereit of which, 

 at 10 per cent, is 100 franks j and if 

 the work be repeated fo many times in 

 the year, the intereft per operation 

 will be •* - * Ifr. 



83fr. 



Hence the litre of bleaching liquor will coft nearly 9 cents 

 in round numbers. * 



* As the price of all thefe feveral items in France rauft materially 

 differ from the fame in England, I have thought it unneceflary to 

 reduce the numbers. 



Eflimate 



