102 STATE HORTICULTURAL SOCIETY. 



cases in which the soil has been brought from a considerable distance. 

 The depth to which soil will thus accumulate depends partly on the 

 nature of the rock and the rapidity of decomposition, partly on the 

 slope of the ground, and partly on the climate. The process of rock 

 disintegration maybe explained in a general way: Almost all rock& 

 are composed partly of solid materials and partly of materials which 

 are slowly dissolved by atmospheric water. Granite gneiss and volcanic 

 rocks are composed of quartz, feldspar and mica. Quartz is unchange- 

 able ; mica is very slowly affected ; feldspar is then the decomposable 

 element. Pure limestone may be regarded as composed of granules of 

 carbonate of lime, cohering by a cement of the same. Sandstone con- 

 sists of grains of sand cemented together by carbonate of lime or per- 

 oxide of iron; where the latter prevails we have a fiae building stone ;^ 

 where the former we have a sandy soil. Slate rocks disintegrate into 

 a pure clay soil because the cementing material is carbonate of lime. 

 The disintegration is caused by the action of the atmosphere and 

 frost." 



This being the composition of different rocks we raise the interest- 

 ing question, how best preserve the soil? How restore "worn out 

 lands ? " What kind of soil is best adapted to trees, plants or veg- 

 etables ? This drives us to the question: How feed our trees, plants 

 or vegetables'? In other words, what is the best fertilizer? Can the 

 soil be best maintained or improved by artificial fertilization or by add- 

 ing the original constituent elements ? Can we add these ? Is there 

 any aflinity between the soil and the tree? Is the wood of the tree 

 composed of the same elements as the soil? Do we find the same 

 elements in the fruit? 



If we dare answer in the affirmative, then the fertilizer becomes a 

 matter of vast importance, because we eat the elements of the fertilizer. 

 Ought that to be clean or refuse from the stable? Why is it that 

 artificial fertilizers were not used until within the last two hundred 

 years ? Why was animal refuse ever used as a fertilizer? This quest- 

 ion will be answered further on. 



"We find" says Hensel, a celebrated German horticulturist, "that 

 all plants, as also all animal bodies (for these are built up from veget- 

 able substances ), after combustion, leave behind ashes which always 

 consist of the same substances, although the proportions of admixture 

 vary with the different kinds of plants. We always find in the ashes, 

 potash, soda, lime, magnesia, iron and manganese, combined with car- 

 bonic, phosphoric, sulphuric, muriatic, fluoric and silicic acids. These 

 ashy constituents give their form and connections to the bodies of 

 plants and animals according to the manner indicated above. Now, in- 



