On the Alkalies of Commerce. 173 



and custom-house duties. I gave this advice to M. Pe'Ietan 

 also. This salt does not always crystallize with facility^ 

 particularly in warm seasons : by this method the manu- 

 facture will go on much faster*. 



Necessity of a prompt and easy JSkthod of proving t/ie 

 Alkalies. 



Among the various alkalies of commerce, none of them 

 offer either soda or potash in their state of purity. The 

 least impure are those which contain merely carbonic acid 

 and water : afterwards come those which contain earths, 

 carbonate of lime^ sulphur, charcoal, and particularly the 

 alkaline muriates, and sulphates, of which it is but top 

 true that for some years a fraudulent mixture has been made, 

 extremely prejudicial to manufactures in which alkali is 

 used. 



For a long time it has been a great desideratum to dis- 

 cover a prompt and easy process for trying potash, soda, 

 natron, and the other alkalies, which might bofboth within 

 the reach of buyers, and certain in its results. The areo- 

 meter, so convenient in the spirit-trade, and even in that of 

 the sulphuric, nitric, and muriatic acids, is insufficient ia 

 this respect. It has been successively suggested to employ 



* Since writing the above memoir, I learnt that M. Carny, to v/hom 

 Fiance is indebted for a remarkably expeditiou; process of manufacturing 

 gunpowder, has formed an establishment at Dieuze, where he has alre:idy, 

 within one year, manufactured twelve hundred quintals of an excellent salt 

 of soda, which he ^ells under three different forms. The first is in a very- 

 dry powder. The second is in irregular masses, and still conraias some 

 water of crystallization. The third is in well formed and colourless crystals. 

 No. 1 equals in alkaline strfngth the best potash extracted from tartar. 

 M. Carny sells it at 200 livres for 100 kilogrammes delivered at Rouen, while 

 the fine Russian potash is sold at the lame price, although 10 per cent 

 Weaker. I rejoice in having an opportunity of publishing this npw obligation 

 of our country towards one of its most respeciable citizens, who has not as 

 yet received a recompense proportioned to his merit. The experimenta 

 begun at Rouen, under the direction of M. Vitalis, upon dyeing cotton red 

 after the Adrianoplc' method, promise the mcM happy results; they already 

 produce a saving of 70 per cent, from the employment of this salt, compared 

 with the best Spanish soda. The manufacture of M. Carny might be raised 

 to 2,.0OO metrical quintals annually ; it i; founded upon theocconomisation of 

 the lulpliate of «ods, of which the salt spring? in France present us v^ith 

 J«Tgt qiiantiticf. 



various 



