A3 A MANURE. 21 I 



bined alkalies; the uncombined acids; are by thefe experi- 

 ments excluded. In fhort, the fait of peat is almofl pure ful- 

 ph&te of iron. 



Remarks. 



\ . The fait of peat is, I apprehend, depofited by evapo- Salt of peat how 

 rations which run over the moors, where it is found; and P roduced « 

 hence I fhould expect many of fuch waters to be ftrongly im- 

 pregnated with it, and in many parts the foil to be tinged red 

 and yellow by ochre. Very likely * on enquiry much iron 

 pyrites will be found on, or near the moors. 



2. The quantity fpread on land isfaid to be fifty bufhels per Its quantity muft 

 acre, which I eflimate at 2,250 pounds avoirdupoife ; this will ^manure* " 

 give near feven ounces and a half per fquare yard. If a larger 

 quantity be applied, it is obferved it will prove extremely de- 

 leterious. This is true alfo of every other manure, fuch as 

 lime, alkaline falts, marine fait, nay, of the dung of animals: 

 for if they be ufed in certain quantities, they poifon plants, in- 

 fiead of promoting their growth. This is equally true in the 

 animal kingdom ; for there is not an article taken as food, or 

 as feafoning, which is not a poifon, if taken in certain quan- 

 tities. A human creature may be poifoned or alimented by and it is hurt- 

 beef or pudding, according to the quantity of them taken into c " f °" y f j*~ j 

 the ftomach. He may be poifoned, or have digeftion greatly condiments alfo 

 affifted by fait, or pepper, according to their quantity. In are * 

 brief, the vulgar notion of the term poifon is erroneous : for 

 by it is conceived that fubftances fo called are in their nature 

 pofitively deftruclive of life ; but the truth is that the moft vi- 

 rulent poifons are, in all reafon and fa£t, only deleterious ac- 

 cording to the quantity applied. White arfenic fwallowed in 

 the quantity of ten grains or lefs, will deftroy life; but in the 

 quantity of one-fixteenth of a grain, it is asharmlefs as a glafs 

 of wine; and further, in that dofe is a remedy for inveterate 

 agues. 



From thefe considerations I conclude, that there is no ad- 

 miffible contradictory evidence to the teftimonies for the fer- 



* " This is," fays Mr. Willaume, " exa&ly the faft. This ful- 



phate of iron, the i'alt of peat, during the heat of the fummer is 



frequently found in a chryftalized ftate, very white, and crackling 



under the feet ; but is deliquefcent in that form, and turns to its 



former dark colour when the air becomes mo\H."— Note hy Mr. Ji 



W. Willaume, 



P2 tillizing 



