360 Transactions of the American Institute, 



same maimer tliat lime displaces it from barn-yard manure and simi- 

 lar manures, as we have just mentioned ; and although the potash of 

 the ashes and the phosphoric acid of the guano or the like, would he 

 left to benefit the plant, the ammonia would be dissipated and lost, 

 and the value of the fertilizer depreciated. Analogous to potash in 

 its action is soda, which, however, with a few exceptions to the rule, 

 enters but slightly into the composition of plants, and ma}" generally 

 be replaced to a great extent by potash. Turnips and mangold- 

 wurtzel, however, i-equire a comparatively large amount of soda, the 

 ash of the former containing upwards of twenty-eight per cent, and of 

 tlje latter a nearly equal amount. This may be most conveniently 

 applied to the soil when required in the form of common salt. We have 

 thus treated in a general manner of " Artificial Fertilizers and their 

 Uses ;" but the limits prescribed for a paper of this kind have prevented 

 us from touching uj^on many things, a knowledge of which is essential 

 to a full understanding of the subject or a just recognition of its 

 importance. For instance, the changes resulting in the mechanical 

 structure of a soil from drainage, the relative capacity of the same 

 for the retention of moisture, and even its color, as enabling it to 

 absorb and retain heat to a greater or less degree, all affect to the 

 same extent the value and action of manurial agents when applied 

 thereto ; yet each one of these would require as much space for full 

 consideration as has been allotted to this essay. There is, indeed, no 

 limit to the subject, and there is no subject of more real interest to 

 the student of science or the searcher into the mysteries of nature's 

 ways. We know, of course, that there is little romance in 

 this topic of wdiich we have tried to treat. The most active 

 imagination can scarcely detect one trace of poetry in a pile of hen 

 roost refuse, and aesthetic taste can have but little exercise in contem- 

 plation of a barrel of guano. No halo of glory clothes Avith lambent 

 light a cart load of powdered bones, and no pathos may be evolved 

 from a sack of crushed and decaying fish. But yet, when we 

 see this foul offal sink into the soil, and, under the action of the 

 rain and the heat and the liglit from heaven, slowly separate into 

 elements that pass into the thread-like rootlets, and into the tremulous 

 leaves, so that from them, atom by atom are built up the blades of grass 

 that give nourishment to the beasts of the field, and the bearded grain 

 that makes bread for the sons and daughters of earth, and the tall trees 

 whose fuel yields light and warmth to hearth stones of happy 

 homes, we may well ponder in amazement at the transformation, and 

 (believe it to be but a new illustration of the moral hidden in tiie old 



