430 BOAKD OF AGRICULTURE. 



III. 

 MINERAL CONSTITUENTS IN PLANT GROWTH. 



CHARLES A. GOESSMANN, Ph. D., 



PROFESSOR OF CHEMISTRY IN THE MASSACHUSETTS AGRICULTURAL COLLEGE, AMHERST. 



[Read before the Massachusetts Horticultural Society, March 18, 1882.] 



A careful examination of the circumstances which have 

 favored the recent introduction of a more rational farm 

 practice for the production of crops, cannot fail to prove that 

 the recognition of the important influence which certain min- 

 eral constituents of plants exert on plant growth in general 

 has contributed more to our success in agriculture than any 

 other one which may be stated. The confidence in the cor- 

 rectness of the current opinion, that the presence of these 

 mineral constituents in an available form in the soil is essen- 

 tial for the reproduction of any plant from its seed, is so 

 firmly established in the minds of thinking agriculturists 

 that we are apt to forget how recent the date when the first 

 comprehensive experimental investigations in that direction 

 rendered the existence of these relations between soil and 

 plant more conspicuous. It seems at the present time 

 almost incredible to notice in the writings of Justus von 

 Liebig that, as late as 1830, one of the leading botanists of 

 the University of Berlin, Sprengel, still asserted that 

 ground bones are of no use as a fertilizer in Germany ; or 

 that the distinguished French chemist, Dumas, even ten 

 years later, considered the mineral constituents of plants a 

 mere incidental feature in the vegetable economy ; or that 

 before 1840, not one pound of Peruvian guano was used 

 upon the farms of Europe, although Alexander von Hum- 

 boldt, in 1814, had described its use as a fertilizer in Peru, 



