1847.] The Organic Matter of Soil. 93 



the idea that It was the principal food of plants. The idea, it is 

 true, was crude, and it will not offend any one at the present time 

 to say that the early notions of farmers and chemists, who had 

 turned their attention to the subject, were crude, and probably, if 

 we insist upon it, were really erroneous. Still, even error, in 

 toto, is rare, and some truth at least is usually mixed with it; that 

 it was a valuable composition in the soil, and performed some 

 function serviceable to vegetation, was a common belief. The 

 error consisted in the misapprehension of the truth, and was not 

 so broad or fatal as that which maintains that it is of no use at 

 all. It is by no means a fatal error to maintain that a substance 

 is important, and yet mistake its function or office. It is one of 

 those errors which belong to theory, and does not necessarily exist 

 in practice. A farmer, for instance, believes that barn yard ma- 

 nure is useful. His belief will lead him to save it, and employ it 

 upon his corn, and this he may do notwithstanding his theory of 

 its action is misapprehended, or may be totally false. The main 

 thing is to be right as to the fact. Still, a correct view of the 

 whole subject, how the organic matter acts, in what way it is 

 beneficial, and how it is related to the inorganic matter, will un- 

 doubtedly increase our power over the products of the earth. This 

 is by no means an irrational view of the subject. If we apply it 

 to some of the most common processes of farming, as plowing, 

 it is evident that the farmer who best understands the object and 

 use of plowing, will derive the most benefit from it. All agree 

 that it is useful, and hence all will plow; still, those will plow 

 the best, and adapt the woik better to the end in view, who best 

 understands its use, than the farmer who has only this naked truth 

 at his elbow, that it is useful, but knows not why or wherefore. 

 Theory, then, to continue the line of remark, is useful; and correct 

 theory eminently useful. At the same time, the fact may, and 

 usually is, more important practically; for the fact leads to the 

 right action, but it may fall short of the benefit it is calculated to* 

 give, when fact and correct theory are conjoined, and go to the 

 work together. Theory and book learning are often ridiculed by 

 the matter of fact man, and yet observation often bears us out in 

 the opinion that in most instances there is not only a great want 

 of facts, but that also when found they are often greatly perverted. 

 But we turn now to the subject more immediately before us. 

 What are the functions which the organic matter performs in vege- 

 tation? Our belief is, that all terrestrial plants, if they do not ab- 

 solutely require it, are at least benefited by it. That it is not taken 

 into the plant in the condition of mould or humus, is proved from 

 the fact that it is not in this condition sufficiently soluble. If then 

 it is useful, it is necessary to maintain that it undergoes certain 

 changes before it becomes the food of plants. It may minister to 



