138 STATE POMOLOGICAL SOCIETY. 



wood growth at the expense of fruit; whereas, on slate, gravel, 

 sand and the like, unprepared, we often see the reverse, i. e. fruit 

 crops at the expense of the tree ; which proves that an orchard, to 

 be both vigorous and productive, muat have all the necessary ele- 

 ments and conditions to make both wood and fruit. 



Not only is the proper preparation of the soil essential to suc- 

 cess, but it is also important to ascertain * " What is the best 

 method of manuring fruit trees? ^^ — their appropriate manures, &c. 



Chemistry proves to us that the alkaline earths, which, by anal- 

 ysis, are found in the ashes of plants and their fruits, are indispen- 

 sable to their development, and that if these elements be wanting 

 in the soil itself, to be taken up by the plants and fruits as their 

 constant food, the latter cannot thrive. Other elements, as the 

 vegetable or organic acids, cannot be dispensed with ; but the 

 absence of one or more of them will not seriously interrupt growth 

 and development. Different families of plants possess these acids 

 peculiar to themselves, not free, but nearly all combined with 

 alkalies. Tartaric acid, always present in the vine, is found in 

 combination with an alkali as a tartrate, phosphoric acid as a phos- 

 phate, malic acid as a malate, silicic acid as silicate, and so on 

 through the series, very few (if any) of the acids being absolutely 

 free or uncombined with its alkali, so that the presence of potash, 

 soda, lime and magnesia in the soil is positivelj' indispensable to 

 the life of all plants, as the carbon, oxygen and nitrogen in the air 

 (the primary elements of the vegetable acids) are also' indispen- 

 sable to their existence. All plants, therefore, must have these 

 alkalies for the support of their vital functions, together with the 

 organic acids generated by the contact of alkilies with the humus, 

 «&c., in the soil, or derived from the atmosphere, &c., each after 

 its kind. A plant or its fruit cannot attain perfectness in devel- 

 opment if the food necessary for the purpose be absent. These 

 elements are not the same in all plants. Soda is the only alkaline 

 found in marine plants; in others are found both soda and potash, 

 sometimes potash and lime, lime and magnesia, &c. The acids of 

 course vary as a natural sequence. 



The whole system of agricultural chemistry depends upon a cor- 

 rect knowledge of the alkaline salts, whether existing in the soil 

 naturally or supplied to it artificially, based upon a knowledge of 

 the wants of each family of plants. Says Baron Leibig, " an em- 

 pirical system of agriculture has administered the same kind of 

 * Report Penn. Fruit Growers' Society, 1873-4, pago 11 — &o. 



