33® French National Injiitute. 



To give to the fame {tuffs that beautiful red colour, known 

 under the name of the Turkifh or Adrianople red, dyers em- 

 ploy foda, oil, gall-nuts, fumach, madder, the fulphate of 

 alumine, and feveral other fubftances. Cit. Chaptal has ex- 

 amined what is the action of the three principal mordants, 

 oil, gall-nuts, and alum, employed in dyeing cotton ; and by 

 defcribing the mod complex and obfcure operations in dyeing, 

 he has fhewn what chemiftry can do towards improving the 

 arts, when the practice of it is directed by a fimple and 

 clear theory *. 



The employment of foda is not confined to the dyeing of 

 cotton ; that brought from Spain is of great ufe alfo in foap 

 manufactories, glafs-houfes for making white glafs, and in 

 bleaching. As France expends annually the fum of four 

 millions for that foreign article, it was of importance to en- 

 courage the cultivation of the plant which furnifhes the fcda 

 of Alicant. In this refpect Cit. Chaptal and Teffier have 

 been of great fervice : the firft, in proving by the experience 

 of many years, that the plant which furnifhes the foda of 

 Alicant may be fuccefsfully cultivated on the fouthern coafts 

 of France ; and that the foda it produces is abfolutely of the 

 fame quality as that of Spain ; and the fecond, by giving all 

 the necefiary inftructionS refpecting the cultivation, and 

 burning of the plant in order to convert it into foda. 



Some years ago Cit. Clouet, a member of the Inftitute, 

 had fhewn the poffibility of converting iron into caft fteel, 

 without, having recourfe to previous cementation. This 

 proccfs, which he has brought to perfection, is the more 

 valuable to the arts which require call fteel, as it may be 

 produced without cementation or natural fteel in every 

 place where there is good iron, a mixture of alumine and 

 filiceous earth, and chalk. 



• It is well known that the goodnefs of artillery depends, in 

 an effential manner, on the operations which relate to the 

 mixture and fufion of the metal. Tin, which forms a part 



t See Chaptal's Paper on this fubicft, page ija, 



of 



