EXCREMENTS RESTORE ASHES OF PLANTS. 173 



the excrements of the horse and of the cow (see Appendix), 

 yield conclusive proof of the nature of the salts contained in 

 them. 



In the solid and liquid excrements of man and of animals, we 



RESTORE TO OUR FIELDS THE ASHES OF THE PLANTS which Served 



to nourish these animals. These ashes consist of certain soluble 

 salts and insoluble earths, which a fertile soil must yield, for they 

 are indispensable to the growth of cultivated plants. 



It cannot admit of a doubt, that, by introducing these excre- 

 ments to the soil, we give to it the power of affording food to a 

 new crop, or, in other words, Ave reinstate the equilibrium which 

 had been disturbed. Now that we know that the constituents of 

 the food pass over into the urine and excrements of the animal 

 fed upon it, we can with great ease determine the different value 

 of various kinds of manure. The solid and liquid excrements 



OF AN ANIMAL ARE OF THE HIGHEST VALUI! AS MANURE FOR THOSE 

 PLANTS WHICH FURNISHED FOOD -TO THE ANIMAL. The dung of 



pigs fed upon peas and potatoes, is in the highest degree adapted 

 as a manure for fields growing peas and potatoes. We feed a 



150 



