2CS VARIOUS METHODS OF HEATING DESCRIBED IN DETAIL. 



the advantages to be derived from them. In short, they are 

 afraid the vines will exhaust the soil within the limits of the 

 range allowed to the roots, and then fail in producing a crop for 

 the want of food. Now I think a very little consideration will 

 prove this to be a groundless fear. Supposing the soil to be the 

 principal repository for the nutriment of the vines, and that it 

 should contain all the substances in abundance, whether solid 

 or gaseous, which form their structure and produce their fruit ; 

 yet it is not necessary to form this border into a mass of nitro- 

 geneous matter to produce these results. Plants, in this respect, 

 are as bad as animals; and a vine-border may as readily be 

 poisoned with excess, as impoverished for the want of proper 

 elements of nutrition. Now I maintain, and I do so upon expe- 

 rience, that the grand requisite to be looked to in the formation 

 of a vine-border is its condition as regards texture, and not its 

 chemical properties. The first secured, the latter can be added, 

 not only when it is first made up, but annually afterwards, and 

 each subsequent time, with as much advantage as at the begin- 

 ning. The food of vines consists chiefly of the elements, car- 

 bon, hydrogen, nitrogen, and oxygen, in some state of combina- 

 tion, together with certain inorganic compounds, amounting to 

 only about 7 per cent., as silica, salts of lime, magnesia, iron, 

 potash, soda, and other bases, combined with sulphuric, phos- 

 phoric, carbonic, silicic, humic, and other acids. These sub- 

 stances can be supplied, in a liquid state, in quantities more than 

 sufficient for the actual requirements of the vine. But their 

 efficacy will very much depend upon the freeness, porosity, and 

 other mechanical qualities of the soil, favorable to the decom- 

 position and recombination of these elements. The general 

 method of renovating a vine-border is by incorporating about 

 half its bulk of manure, to the manifest destruction of many of 

 the best roots, — for the best are always on the surface, — 

 besides incurring a vast amount of labor and expense, which 

 labor and expense would be sufficient for at least a dozen years. 

 Salts of ammonia, for instance, in their various states of com- 

 bination, are known to exercise a powerful influence on the 

 growth of grape-vines. Now, by adding, say, 10 tons of the 

 best manure to the borders, we supply them with about 85 pounds 



