38 QUINCE CULTURE. 



land fertilized a long time with superphosphates, there 

 is an accumulation of fertilizing material that salt makes 

 available. The lime and phosphoric acid lock up what 

 the salt liberates. As good results were obtained with 

 one quarter salt and three quarters phosphate, as from 

 all phosphate without the salt. The salt and phosphate 

 in equal parts produced a fine crop of corn on a mucky 

 soil. Two hundred pounds of salt on three-fourths of 

 an acre gave me the best crop of German millet I ever 

 grew. It will be found valuable with quinces, pears, 

 plums, peaches, and apples. 



Heavy soils will usually be found to contain enough 

 potash, but in an insoluble condition. Ordinarily a 

 good top dressing of salt will make this potash available 

 to promote a fruitful condition. The German potash 

 salt, kainit, and muriate of potash will be found service- 

 able to most orchards. Nitrogenous manures stimulate 

 the growth of leaves more than the fruit. The mineral 

 manures, such as potash and salt, aid most in perfecting 

 the fruit, especially the seeds, the thing of greatest effort 

 in Nature's laboratory. 



The value of any fertilizer is determined by the amount 

 of potash, phosphoric acid, and nitrogen it contains. 

 Nitrogen is expensive as an ingredient in the commercial 

 fertilizer, and if it can be obtained free from the air, it 

 will be a very great saving to us. 



"The atmosphere is chiefly composed of oxygen and 

 nitrogen ; and water, of oxygen and hydrogen; and as 

 there is always in the air more or less water, the element 

 hydrogen is always present. Now under certain circum- 

 stances, the nitrogen and hydrogen combine in the air and 

 form ammonia. The oxygen and hydrogen in the air are 

 supposed not to be united in a chemical combination, but 

 to form merely a mixture. Hence this nitrogen is called 

 the free nitrogen of the air, as distinguished from that in 

 ammonia, which is not free," 



