192 MASSACHUSETTS HORTICULTURAL SOCIETY. 



Mr. Hadweu, as Chairman of the Committee on Discussions, 

 announced for the next Saturda}' a paper l\y Professor G. C. 

 CaUlwcll, of Cornell Uuiversit}', Ithaca, N. Y., on "Nitrogen: 

 Why the crops must have it and where they must get it." 



BUSINESS MEETING. 



Satukday, March 27, 1886. 

 An adjourned meeting of the Society was holden at 11 o'clock, 

 the President, Henry P. Walcott, in the chair. 



No business being brought before the meeting it was dissolved. 



MEETING FOR DISCUSSION. 



Nitrogen : "Why the Crops Must Have It and Where They 



Must Get It. 



By Professor G. C. Caldwell, Ithaca, N. Y. 



In beginning the study of the atmosphere as a source of supply 

 of the nitrogen of vegetation, we are at once confronted with the 

 familiar fact of the abundance of this substance existing there in 

 the free or chemically uncombined state, it being simply mixed 

 with the oxygen ; which is also present in large quantity. This 

 supply of nitrogen would furnish, if the crops could use it, an 

 amount a hundred thousand times greater than the most greedy of 

 them could dispose of. The first question which it is natural that 

 Ave should consider is, Cannot plants force this free nitrogen into 

 those chemical combinations containing nitrogen, which form such 

 an all-important part of the contents of their cells, and for pro- 

 ducing which they must have nitrogenous food of some kind? 



It ouglit not to be necessary to discuss this question now. It 

 has been demonstrated, by the most com[)etcnt investigators who 

 have ever entered the field of agricultural research, that plants 

 cannot assimilate the free nitrogen of the atmosphere — that, in 

 other words, while it is in the free or chemically uncombined state, 

 it is of no use whatever for plant food. Houssingault, in France, 

 now one of the oldest living chemists of renown — whose work 

 commands the highest confidence throughout the chemical world — 

 was the first to investigate this great question in such a manner as 



