PHOSPHORUS AND THE PHOSPHATES. 11 



On the general distribution of the phosphates, it is quite interesting to know that the 

 phosphate of lime is distributed to the outer envelopes of a plant, the bark, cuticle, rind of 

 fruits, etc. ; while the phosphates of magnesia and iron pass to the interior, or to the seed, 

 kernel or grain. These seem therefore especially designed for the animal tissues. Mem- 

 brane and bone, blood and muscle, must contain a definite quantity of the phosphates in a 

 healthy state ; and when they are deficient in quantity, the bones are soft and flexible, 

 and refuse to support the weight of the body. 



Much has been said of the importance of supplying nitrogenous matters to soils. The 

 phosphates can never be derived from the atmosphere, or from rain water, nor are they 

 furnished by any of the ordinary processes of nature : hence, if they become exhausted, 

 direct application must be made of some substance which contains them. They must be 

 supplied by labor, and by somewhat expensive materials. Nitrogenous matters, however, 

 are constantly being added to soils, by unceasing operations or agencies independent of 

 man. The rain brings down ammonia to the earth, so that nitrogen can never be totally 

 absent from any soil, though it may be deficient in quantity, or insufficient to supply the 

 wants of artificial crops ; but the phosphates can not be obtained when the soil has been 

 exhausted of them, except by waiting the slow decomposition of rocks, or by a direct appli- 

 cation of some material which contains them. It is towards this one thing, the supply of 

 a sufficient quantity of substances abounding in the phosphates, that the farmer should 

 direct all his measures. Other substances, though they may be important, yet are fre- 

 quently so abundant that there is really no difficulty in obtaining them. This is the case 

 with sulphuric acid, abundance of which exists in gypsum, and other cheap salts of the 

 alkalies and alkaline earths. 



Not intending, however, to diminish the weight of opinion in regard to the importance 

 of adding nitrogenous matters to soils, it is notwithstanding proper that correct views should 

 be entertained upon this subject; and I think that the statement of Liebig, in his work 

 entitled " Chemistry in its applications to agriculture and physiology," puts the question 

 in its proper light. He states, p. 75, that " the most decisive proof of the use of strong 

 manure [strong in nitrogen] was obtained in Bingen (a town on the Rhine) , where the 

 produce and development of vines were highly increased by manuring them with such 

 nitrogenous manure as the shavings of horn, etc. ; but after some years, the formation of 

 wood and leaves decreased, to the great loss of the proprietor, to such a degree that he 

 has long had cause to regret his departure from the usual methods, ascertained by long 

 experience to be the best. By the manure employed by him, the vines had been too 

 much hastened in their growth : in two or three years they had exhausted the potash in 

 the formation of fruit, leaves and wood, so that none remained for future crops, his manure 

 not having contained any potash. There are vineyards," he remarks, " upon the Rhine, 

 the plants of which are above one hundred years old, and all of them have been manured 

 with cowdung, a manure rich in alkaline ingredients, but poor in nitrogen." The same 

 system of manuring would end in the same disaster in all cultivated crops. 



