41 



adults. If only a small portion of soil is at first employed, 

 and portions more and more enriched, are from time to 

 time added, as the roots ma}^ extend, we are still liable to 

 stumble on an objection, almost as important, though of 

 a somewhat different nature ; for we can in that case 

 scarcely fail to injure the spongioles of the roots in a 

 greater or less degree, and the injury thus sustained, 

 will consequently act as a check in the progress of their 

 developement. These considerations seem at once to 

 mark the propriety of applying liquid manures in highly 

 artificial cultivation ; they can be supplied in this state, 

 when the plants are in such a mature and advanced state 

 of growth, as from time to time to require their aid; 

 and their fertilizing properties being held in solution by 

 the fluid medium in which they are conveyed, they are 

 just in the condition to be taken up at once by the rootlets. 

 It must still however be recollected, that whilst even im- 

 palpable powders cannot as such be made to minister to 

 the nutrition of plants, so neither can gross liquids effect 

 this purpose : it is clear limpid fluids, only, which can 

 be received by the delicate spongioles, and therefore the 

 so-called manure water, when applied of the consistency 

 of mud, is not only in an unfit state to effect its purpose, 

 except by the addition of a more bountiful supply of 

 pure liquid, but it is also liable to act injuriously by rea- 

 son of the concentration of the strength or powerful 

 qualities of the manure, and by counteracting the open 

 texture of the soil. Manure water, therefore, from what- 

 ever source it may be derived, though not necessarily a 

 colourless, should without question, be a limpid fluid ; 

 if otherwise applied, it will at once destroy one of the 

 best qualities a soil can possess, viz. porosity. 



