84 W* Principles of Part IL 



by to putrefy : Quand elks ont cte pourrm 

 jufyue a ce point on elks per dent leur nommes 

 four prendre celui de terreau y elks ont fer- 

 mente vivement et fubitement avec les acides^ 

 que je verfes dejjut. Au lieu que Fefprit de 

 nitre verfcfur de fuilles feches, oufur defuilks 

 jimplement commence a pourrir^ nici produit 

 aucune fermentation fenjible. This experiment 

 puts the queftion beyond all doubt* 



FARMERS have difcovered, by long ex- 

 perience, that the dung of different ani- 

 mals differs very much, as to the quantity 

 to be uied, and the ground upon which it 

 ought to be laid. A much fmaller quan- 

 tity of pigeons dung muft be employed 

 than of any other; and even that mould 

 be laid on cold wet foil. The dung of 

 iheep and hogs feems, by experience, to 

 have the preference to all others. Thefe 

 different effects depend on the different 

 quantities of oil and volatile falts in the 

 dung ; and thefe again on the food of the 

 animal, on the time it flays in the inteftine 



canal, 



