Vn Cbiis. ■2^9' 



in fotil am.) nasty places, turns to a sept'de of potash, by 

 attracting and neutralizing the septic acid recently engen- 

 dered in such situations. Very commuaiv too this alkali is 

 found to be combined with sulphuric acid into a sulphate of 

 potash; and lately on exaniimng some curious samples cf 

 this salt from the manufactories, 1 found theai to coiitaia 

 phosphoric acid. 



In these iwo latter cases, sometimes external causes, and 

 at other times the woods burned, ftarnish a quantity of" 

 sulphur and phosphorus, which' acidifiable bases first tura 

 to acids during the process of combustion, and then the 

 jievvly formed acids connect themselves with the potash to 

 constitute compound salts. Frequently likewise muriate of 

 soda is discovered in wood ashes; but this seems to be de- 

 rived from the culinary salt employed in cooking. 



After these saline substances are extracted by water in th-e 

 course of lixiviation or letching, a large quantity of earthy 

 matter remains behind. 7'he proportion of tlws varies in 

 the ashes of different vegetables, but in that of sound oak 

 and hickory perhaps amounts to eight-tenths of the whole. 

 In this state it is called lefchcd, dead, or soap-boilers'' ashes, 

 and is bought at a high price by farmers in the neigh- 

 bourhood of New York for manure. In its crude condi- 

 tion, as taken from the vat* or letch-tubs, it abounds v^iti; 

 charcoal, soot, and other half consumed vegetable sub- 

 stances which had escaped the destructive force of the fire. 

 Particles of silicious and argillaceous earths are generally- 

 present, derived in all probability from the sweepings of 

 doors, thti crumbling of chimneys, and other external 

 sources. Besides these there is found a quaa-tity of iron; 

 though I have not found any of the ninngauese which some 

 experimenters talk of. But above all, this residuary mass; 

 abounds in lime, which is intentit)nally added, in its caustic 

 state, to attract carbonic and phosphoric acids from the 

 potash, and tliereby to render that alkali quick and active; 

 or, in maritime situations in America, a large admixture of 

 calcareous earth is derived from the roasting of clams, 

 oysters, aud other testaceous animals, 3.nd the addition of 

 their shells to the ashesv But by Kir tlie greatest proportioa 

 of Ictched ashes consists of a pccidiar kind of ca.th, which 

 remains after all the before-mentioned materials i)J-e sepa- 

 rated. This earth is of a whitish colour and alkaline qua- 

 lity, as you will see by the sample I herewith eeud you for 

 cxjK-naients. I think it diflers materially from lime, ba- 

 r^tes, nia^esia, strontiaiVj or any other known species of 



t-anh. 



