40 



the ground which is constantly undergoing the process of fruc- 

 tification for agricultural purposes. The greensward, which 

 will constitute the principal feature of the park, the chief ele- 

 ment of whose beauty and value consists in its being firm and 

 compact cannot be disturbed by the plow or the spade, to add 

 new fertilizing power to the soil, without destroying it altogether. 

 It is for this reason that we should closely study the constituent 

 qualities of the soil, to know precisely what is absent, that is 

 essential, and what should be added to increase its fertility. 

 In truth, we should aim to attain at once the highest degree of 

 fertility of which the soil is capable. Mannre on some soils is 

 unnecessary ; on others, indispensable. Soils vary from great 

 fertility to absolute barrenness ; and the process of manuring 

 is the artificial application of substances to soils, or their incor- 

 poration therewith, in order to increase their productiveness. 

 The application of manures must be regulated accordingly, by 

 a proper knowledge of the soil which is to be fertilized. Chem- 

 ical analysis has been the means of facilitating this inquiry. 

 Its success has been such that the most barren wilderness could 

 be rendered fertile. The only question necessary to be dis- 

 cussed, therefore, when such a restoration is required, is the 

 simple one of expense. 



There are two theories of manures — the humus and the 

 atmospheric ; the first being that of Saussure, the last of Liebig. 

 The humus theory regards " vegetable matter of soils and man- 

 ures as merely applying inorganic matter, in a fluid form, to the 

 roots of plants." The atmospheric theory considers "nutri- 

 ment to be furnished to plants, and manurial action maintained, 

 only by means of substances which either originally possess, or 

 have eventually assumed an inorganic form." 



Whichever theory we assume, the practice is the same. We 

 must first discover the ingredients of a fertile soil ; secondly, 

 we must analyze the soil we have to fertilize ; thirdly, we must 

 supply, in the unfertile, the ingredients which it lacks, in order 

 to become the same as the fertile. A perfect soil is composed 

 of many ingredients, such as organic matter, silica, alumina, 

 magnesia, lime, oxide of iron, potash, carbonic acid, etc., etc. 

 Consequently, if potash is wanting, potash must be supplied ; 

 if magnesia is wanting, magnesia must be supplied, etc. 



Organic matter is a sine qua non of fertility, but if more 



