124 METHOD OF BLEACHING PAPER. 



the inattrafs to half its depth in water moderately heated, agi- 

 tating it from time to time. The folution will be effected in 

 two hours, after which it is fo be diluted in 992 parts of water. 

 This is the proof liquor. The ftronger the bleaching liquor, 

 ' the greater number of parts of the folution of indigo it will 

 render colourlefs, and we may by this proof determine the 

 / dofes of each kind of bleaching liquor to be employed, toge- 



ther with water, fo as to compofe a bath proper for immerfing 

 the fubftance intended to be bleached. 



One part by meafure of the bleaching liquid prepared as 

 before mentioned, will ufually deftroy the blue colour of nine 

 parts of the proof folution of indigo ; it was of the fame 

 ftrength as that of Javel, prepared by Citizen Alban. 

 « 



Choice and Preparation of the Rags. 



Selection of the The flrength or tenacity of paper depends upon the ftaple 

 materia s for Qr ^ re Q f t j ie mater i a i f rom wn i cn ^ is made. Raes of new 



paper, quality or » 



rags, &c. cloth and cordage compofe a paper more tough than old rags, 



and the firft of thefe materials prefents a great variety on ac- 

 count of the quality of the hemp or flax of which they are 

 formed. Rags of fine new cloth, whether raw or bleached by 

 the oxigenated muriatic acid, Hand in the firft. rank, after 

 which cordage and old rags may be claffed. 



Bank or note Paper intended for bills of exchange, or other commercial 



paper. an( j j e g a j m f trum ents ought to be tough, in order that it may 



not be eafily torn when thin, for this paper the materials 

 of the firft clafs mull be intirely, or in large proportion em-* 

 ployed. The price which the confumers are difpofed to psy 

 for this article, is fufficient to indemnify the manufacturer for 

 his care and induftry, as this kind of paper is fold in France 

 for 5 or 6 francs the kilogram. 



Common paper. The other papers alfo require to be more or lefs tough, ac- 

 cording to their thinnefs, and the ufe to which they are 

 applied, but a clear white colour is fought in paper of every 

 defcription. The firft operation to which the rags are fub- 

 jected is forting, in order that each branch of the manufacture 

 may have its appropriate material, after which they are cut 

 with fhears into pieces of about one decimeter, or three or 

 four inches fquare. 



I will fuppofe that the object of the manufacturer is to obtain 

 , paper of a beautiful white. If it is intended to be thin, fo 



that. 



