138 Review of Essays on Calcareous Manures. 



Art. XIV. — Essay on Calcareous Manures, hy Edmund Ruffin. 



Second Edition. Shellbanks, Va., 1835. 8vo. pp. 116. 

 On the use of Lime as a Manure, by M. Puvis, translated for the 



Farmer's Register. Shellbanks, Va., 1835. 



There is no one of the useful arts to which the application of 

 Chemical Science may be made of as much importance as to agricul- 

 ture. We cannot indeed inquire in the minute and dehcate processes 

 by which nature elaborates the inert matters of the soil, and converts 

 them into the living plant ; but we can examine that organized ve- 

 getable, and find what elements enter into its composition, and by a 

 similar examination of soils can determine whether they contain the 

 substances from which the plant ranst obtain its growth, or not. If 

 they do not, the addition which will be efficient in promoting the 

 growth being thus determined, chemical researches will again show 

 the source whence it can be derived in the most economical manner. 

 So also soils may contain compounds which, if the proper food of 

 some plants, may be noxious to others ; chemistry will detect these, 

 and point out the means of neutralizing their injurious action. 



Instead then of the decreasing fertility of soils which pohtical econ- 

 omists assume, in opposition to some well known facts, or which the 

 general experience of our own country would seem to demonstrate, 

 we might infer that good soils could be kept up to their original 

 state, and inferior soils improved until they became equal to the best : 

 that nothing in fact except climate would oppose a limit to the ap- 

 proach of agricultural product to the maximum. 



Such results, however probable in appearance, have been far 

 from being attained, or even approached. Agriculturists rarely 

 take the trouble to learn even the elements of science, and if the 

 direct force of obvious example occasionally leads to the introduction 

 of new machines and improved processes which are merely mechan- 

 ical, those which chemical science would indicate are rejected as 

 unintelligible and visionary. On the other hand the student of sci- 

 ence can rarely or never acquire the practical skill, the knowledge of 

 the mode of performing and directing agricultural labor, on which 

 the practical farmer properly prides himself, and without which the 

 best theory will lead to no profitable result. 



In the application of chemistry to the analysis of vegetables, chem- 

 ists have usually neglected to examine substances of the greatest 



