644 



THE SOUTHERN PLANTER. 



pies, The last result is the coriversion ol" 

 the remaining solid parts, soluble in water, 

 to different gases, or aeriform fluids, high- 

 ly expansive, and which must, as forme*d, 

 burst forth from the confined space in the 

 soil, to rise in the air. When such 

 changes, of insoluble to soluble matter, 

 and finally to aeriform, occur in a heap or 

 body of manure, not in immediate con- 

 tact with soil, and of course not to be 

 *drawn upon by the roots of growing 

 plants, then the successive products are 

 more or less exposed to waste ; and when 

 they reach the last or gaseous state, their 

 escape and total loss is inevitable. If the 

 changes and successive steps of decom- 

 position took place in vegetable or mixed 

 putrescent matters dispersed upon or in- 

 termixed with soil and within reach of the 

 roots of enough growing plants, then noth- 

 ing would be lost; because, as fast as the 

 parts became soluble, they would be ab- 

 sorbed and put to use. And even if, un- 

 der these circumstances, some gaseous 

 products should be slowly evolved, it is 

 most probable that they should be dissolv- 

 ed in the moisture of the soil, and 

 thus pass into and help to support the 

 plants. 



The general changes and results of de- 

 composing manure are the same, and as 

 above described, without respect to the 

 rate or manner of fermentation. If the 

 manure be in mass, as left thickly cover- 

 ing a winter's cattle-yard, or is subse- 

 quently heaped, the fermentation will pro- 

 ceed with more or less energy, according 

 to the degree of exposure to, and combin- 

 ed action of the three agents of fermenta- 

 tion, heat, air, and moisture. And the 

 action will be the more quick in propor- 

 tion to the richness of the mass in animal 

 matter : or such as is the most putrescent, 

 and which, therefore, serves as a leaven 

 to excite fermentation in the whole mass. 

 In such condition, and by too violent fer- 

 mentation, the present or early acting 

 value of the whole body, for any one time, 

 may be greatly increased, by the great 

 bulk of insoluble and inert materials being 

 to considerable extent, made soluble. And 

 all the previous gaseous products were 

 driven off and lost by the same operation ; 

 aBd if thus remaining, the then soluble 

 parts also in their turn, will become gase- 

 ous and lost in like manner. 



If, on the contrary, the manure, when 



fresh, and before fermentation had made 

 much progress, had been diffused through 

 the soil, the same changes would have oc- 

 curred, though more gently and slowly ; 

 and even the :f;ame losses — unless growing 

 plants were present, and sufficiently nu- 

 m.erous to take up the manure as fast as it 

 became fit for their use. 



My remarks have led me to anticipate 

 incidentall}^, an opinion which ought to be 

 more fully presented. This is, that the 

 extractive and soluble parts of putrescent 

 manures form the food of plants. This 

 doctrine is that maintained by the great 

 agricultural chemist, Davy ; and clear and 

 j indisputable as he has made it appear, the 

 doctrine was not only opposed to previous 

 'and received opinions, which are now left 

 j without an advocate, but is now opposed 

 I by the more recent and fashionable au- 

 thority of Liebig. But it is not my pur- 

 pose here to examine or discuss opposing 

 opinions ; and they are thus slightly re- 

 ferred to, merely to avoid producing the 

 same in.pression, that Davy's opinion had 

 been adopted and still adhered to, for want 

 of comparin^them with those, and espe- 

 cially the latter opinions, of others. Davy 

 says : 



" Vegetable and animal substances de- 

 posited in the soil, as is shown by univer- 

 sal experience, are consumed during the 

 process of vegetation ; and they can only 

 nourish the plant by affording solid mat- 

 ters capable of being dissolved by water, 

 or gaseous substances capable of being ab- 

 sorbed by the fluids in the leaves of the 

 vegetables. But such parts of them as 

 are rendered gaseous, and that pass into 

 the atmosphere, must produce a con\para- 

 tively small effect; for gases soon become 

 diffused through the mass of the surround- 

 ing air. The great object in the applica- 

 cation of manure should be, to make it af- 

 ford as much soluble matter as possible to 

 the roots of the plant, and that in a slow 

 and gradual manner, so that it may be en- 

 tirely consumed in forming sap and or- 

 ganized parts. — UlgrH Chem., Lecture 



The concluding sentence of this pas- 

 sage may be considered as the text of my 

 discourse — the rule which I desire to be 

 strictly followed in practice, and the test 

 to which I submit the details of the par- 

 ticular mode of applying manure, here 

 recommended. 



