[ 171 ] ' 



< 

 XXTV. On the Alkalies of Commerce, and on the least ex- 

 pi-nsh'e PrvCess for aicertawing their commercial P^alne hy 

 Means of the Instrument cailrd the Alkali - met er * . Read 

 to the Arndemy tf Roiien, 5 Thermidore, An, 13, hj 

 M. DjtSCi.oizii.LKs senior f. 



American Potash; Process for oIi(aini/tg if. 



JL HE name of American pota«h is given to an alkaline sub- 

 stance, in coiTip ct masses which have visibly undergone 

 fusion. This aikali seems to be the produce ot a ley of 

 ashes and lime, with the addition of sea-salt. The result 

 is a very deliquescent and caustic substance, susceptible of 

 entering into fusion iong before becoming red-hot. If the 

 proportions oi" sea-salt and lime have been sufficient, all the 

 potash is combined with tlieacid <<f the former, and has sepa- 

 rated the soda, at the same time that llie lime is precipitated 

 in carbonate: thus this kind of aikali nmst be considered as 

 a mixture of caustic soda and muriate of potash. That 

 which is red owes its colour to sulphur and charcoal : it 

 alsa partly owes this colour to a little iron. There are first, 

 second and third sorts of An)erican potash. The laundresses 

 oi Pans frequently pay much more for them than tiiey are 

 worth in point ot alkaline properties. The same efi'ccts 

 might be produced if they added to common potash or to 

 wood ashes a small quanty of quick-lime, with this difference, 

 howtvfr, that thtir expense would be considerably dimi- 

 nished. To conclude, all the American potashes I examined 

 also coiilgin carbonic acid. In the departments of France 

 where sa't is male, the mix ure of sea-salt an<llime with 

 ashes, before their hxiviation, nn^ht be turned to great 

 profit. It is a very simple operation, and I only speak of 

 it from some experiments made upon a very large scale, 



* N.B. The first part of this memoir consisting merely of some well 

 known facts n-lative to the orljjiii and vario'.is forms and ;i;iincs of the 

 alltalie* of commerce, we ;jive here only the new points of view in which 

 poUih ;ind soda arc presented — A'o/c ly the Freiak F.duor. 



i Frutn Anitaltt dt Cliimit, torn. Ix. p. 17. 



v-liich 



