4S ELEMENTS OF 



more immediate and apparent than that of hard and 

 dry animal matters — the action of which is, neverthe- 

 less, stronger, and continues for a longer period. 



The refuse of the different manufactories of skin and 

 leather form very useful animal manures; such as the 

 shavings of the currier, furrier's clippings, and the offals 

 of the tan-yard and of the glue-maker. The gelatine 

 contained in every kind of skin, is in a state fitted for 

 its gradual decomposition ; and when buried in the soil, 

 it lasts for a considerable time, and constantly affords a 

 supply of nutritive matter to the plants in its neighbor- 

 hood. These manures contain nitrogen as well as phos- 

 phates, and consequently are w^ell fitted to aid the pro- 

 cess of vegetable growth. 



From what has been stated, we may arrive at the fol- 

 lowing conclusions : — 



1. That fresh human urine yields nitrogen in greater 

 abundance to vegetation than any other material of 

 easy acquib^ition ; and that the urine of animals is valu- 

 able for the same purpose, but not equally so. 



2. That the mixed excrements of man and animals 

 yield (if carefully preserved from further deconiposiiion) 

 not only nitrogen, but other invaluable saline and earthy 

 matters that have been already extracted in food from 

 the soil. * 



3. That animal substances which, hke urine, flesh, 

 and blood, decompose rapidly, are fitted to operate im- 

 mediately and powerfully on vegetation. 



4. That dry animal substances, as horn, hait, oi 

 woollen rags, decompose slowly, and (weight for weight) 

 contain a greater quantity of organized as well as un- 

 organized materials, manifesting their influence it may 

 be for several seasons. 



5. That bones, acting like horn, in so far as their 

 animal matter is concerned, may, according as they have 

 oeen more or less finely crushed, ameliorate the soil by 

 their earthy matter for a long period, (even if the jelly 

 they contain have been injuriously removed by the size- 

 maker,) permanently improving the condition and adding- 

 to the natural capabilities of the land. 



