PROCEKDINGS OF THE FABMEBa' CLUB. 459 



under the surface, thus forming a million tubes serating the soil, 

 and supplying conditions of fertility. 



Prof. Nash. — Will you state your views as to the comparative 

 benefit of plowing in or feeding off clover. 



Prof. Mapes. — There are two questions which arise from the 

 feeding off the clover, one is, that so much of the clover as will 

 go to make up parts of the new organism of the animal is, of 

 course, robbed from the soil, but so much of the clover as, after 

 being appropriated by the animal, forms a portion of his excre- 

 tions, is increased in value, enough so perhaps to compensate for 

 the whole or a part of the missing portions. They are returned 

 in a progressed condition, for we should bear in mind that it is 

 not the constituents that have value, but the condition of those 

 constituents ; for instance, chemically considered, the constituents 

 of a man do not differ at all from the same constituents found in 

 the rocks, yet you Avould find it very dilHcult to combine rock a 

 in such a way that they would plant potatoes or deliver a lecture 

 on manures. The constituents are the same in a tree as in the 

 lowest organisms of nature, hence it follows that merely knowing 

 the constituents of a -manure does not always eriable us to deter- 

 mine its true character. The analysis of a manure, unless it can 

 point out the condition of every constituent in it, will give you 

 no clue to its value. The gentleman (Dr. Thompson) spoke to 

 you this morning of the phosphates contained in the ashes he 

 used. NoAv we have phosphates in the Hurdstown rock, but they 

 are not worth, to the agriculturist, 6^^ cents per ton, and we 

 have phosphates in bones, which have a high value. The 

 phosphates in ashes, having been in organic life a million times, 

 are ready to enter organic life again, and a pound of them is 

 worth more than a pound of sombrero guano, or any other volca- 

 nic product which is phosphatic in its composition. One might 

 as Avell talk of the arsenic in a pane of glass, when the object is 

 to kill a rat, because the analysis of glass shows that it contains 

 arsenic, as to talk of phosphates, for fertilizing purposes, unless 

 they are in the proper condition to be appropriated by plants. 

 The gentleman also remarked that he wished he could sell yqu 

 the ashes of straw ; it was evident that he believed the ashes of 

 straw to have a much greater value than the ashes of wood ; not 

 that they contain more potash, but because that which they do 

 contain is in a higher condition, better capable of feeding the 

 higher classes of plants than the same quantity of other potash. 

 Do not forget that of most constituents, in all soils, the quantity 



