RECAPITULATION. 159 



we may avoid, and is highly beneficial to every kind of clover. 

 Perhaps it is the [humate, or some other vegetable] salt of lime, 

 formed by the calcareous manure combining with the acid of the 

 soil, which, not meeting with enough vegetable matter to combine 

 with and fix in the soil, causes, by its excess, all these injurious 

 effects. 



CHAPTER XIX. 



BECAPITULATION AND MORE FULL STATEMENTS OF THE EFFECTS 

 OF CALCAREOUS MANURES. 



PROPOSITION 5 continued. 



From the foregoing experiments may be gathered most of the 

 effects, both injurious and beneficial, to be expected from calcareous 

 manures, on the several kinds of soils there described. Information 

 obtained from statements in detail of agricultural experiments is 

 far more satisfactory, to the attentive and laborious inquirer, than 

 a mere report of the general opinions of the experimenter, derived 

 from the results. But however conclusive may be this mode of re- 

 porting facts, it is necessarily deficient in method, clearness, and 

 conciseness. It may therefore be useful to bring together the 

 general results of these experiments in a somewhat digested form, 

 to serve as rules for practice. Other effects of calcareous manures 

 will also bo stated, which are likewise established by experience, 

 but which did not belong to any one accurately observed experiment. 



The results that have been reported confirm in almost every 

 particular the chemical powers before attributed to calcareous ma- 

 nures, by the theory of their action. It is admitted that causes 

 and effects were not always proportioned, and that sometimes 

 trivial apparent contradictions were presented. But this is inevi- 

 table, even with regard to the best established doctrines, and the 

 most perfect processes in agriculture. There are many practices 

 universally admitted to be beneficial ; yet there are none of these 

 which are not found sometimes useless, or hurtful, on account of 

 some other attendant circumstance, which was not expected, and 

 perhaps not discovered. Every application of calcareous earth to 

 a deficient soil is a chemical operation on a great scale. Decompo* 

 sitions and new combinations are produced, and in a manner gene- 

 rally conforming to the operator's expectations. But other and 

 unknown agents may sometimes have a share in the process, and 

 thus cause unlooked-for results. Such differences between practice 

 and theory have sometimes occurred in my use of calcareous ma- 



