274 P'rencb National Injlttute. 



The. moment of fubjeftine: the rags to the aclion of tlie 

 acid is not a matter of indlflTerence. If they arc bleached 

 entire, as the inleiior of each thread docs not experience any 

 aftion, this would afterwards alter the whitcncfs of the 

 parte; and if the workman lliould wait till they were ahfo- 

 lutelv reduced to pulp, the pulp would fornr a body with 

 which it would be difficult to mix the acid intimately. The 

 matter then mull be taken at a mean Hate between that of 

 ratrs and that of pulp completely triturated. For this pur» 

 pole the rags are made to pafs under a fir(l cylinder to fepr» 

 rate the fibres; they are then fubjcded to bleaching, and 

 then converted into pulp bv means of another cylinder. 



If the raes are raw, two batlis of oxygenated muriatic acid 

 or bleacliing liquor, and one of fulphuric acid, are employed. 

 If tlu'v are white, one bath of the liquor and one of fulphu- 

 ric acid will be hifficicnt. 



The muriatic acid is prepared either with common muriatic 

 acid and oxide of manganefe, or by means of fulphuric acid 

 with oxide of mantj;anefc and muriate of foda (common fait). 

 The laft method Ts the molt economical ; 25 parts of oxide 

 of manijanefe, 70 of conunon fait, and 120 of fulphuric acid, 

 of 3 I degrees ofdcnfity (bv the areometer), will be lufficient 

 to charge a receiver of 270 gallons. The ftrenglh of this 

 Jiquor is appreciated bv means of a folution of indigo, which 

 is prepared bv dilTolving one part in weight of indigo in feven 

 parts of fulphuric acid concentrated to 66 degrees, and which 

 is then diluted in 992 parts of water, according to the me- 

 thod of Delcrozitles. When one mcafure (in volume) of 

 the bleaching licjuor annihilates the colour of nine of this 

 folution of indigo, the bath prf)per for l)lcaching 110 pounds 

 avoirdupoife of raos, after being fubjcftcd to the firll cylin- 

 der, is compofed of 24 gallons of inch bleaching liquor di- 

 luted in 120 gallons of pure water. 



The expcnfe of theic diflcrent operations will be moderate, 

 when one bath of bleaching licpior and one of fulphuric acid 

 are emploved, which is gencrallv the cale, and the paper is 

 exccedinglv beautiful. There is no doubt therefore that the 

 price of paper will be much diminiflied, wlicn the method 

 here explained is employed and brought into general prac- 

 tice. 



On tie Fixity which Antimony acpiires by its AUoy with Tin. 



When attempts were made to rellore to connuerce that 

 prodigious quantuv of metallic matters which had been em- 

 ploved in making bells, it was found that the firfi: operation 

 nccellary was to feparatc the copper and tiii, which formed 



6 llKif 



