80 



MASSACHUSETTS AGRICULTURE. 



which has germinated in water, and has shot forth roots, is 

 placed in a sohition containing the food of the maize in the pro- 

 portions in which they exist in the ashes of the plant, if at the 

 same time there has been added to it, so much nitrate of 

 ammonia, that to every part of phosphoric acid in the solution 

 there are two parts of nitrogen, and if finally it has been 

 diluted with distilled water to a concentration of three parts 

 of solid matter per 1,000 parts. In this manner may be 

 matured fully formed plants which attain a height of sev^en feet. 



We are therefore justified in believing that the corn-plant 

 will grow and mature its crop, when supplied with food of 

 the character and proportion as found in the plant. 



Again, if we examine with care the experiments of Knap, 

 another reliable German experimenter, not only is our con- 

 clusion justified, but we have an additional fact of interest; 

 viz., that throughout the period of growth, the phosphoric 

 acid supplied, was all absorbed by the plant, while the amount 

 of potash assimilated was far more variable. This Avould 

 lead us to suspect that more of the potash is as accidental 

 ingredient of the plant, than of the phosphoric acid. In other 

 words, that circumstances might determine the plant to absorb 

 more potash, in excess of its real requirements for grain 

 growing, than of phosphoric acid, and if this were so, to 

 indicate this change, by a greater or less amount of foddering. 



Result of Knap's Experiment with the Maize Plant. 



In column A is given the quantity of the material received 

 by the plant at a particular period. In column B is given the 

 material found in the solution at another determinate period. 

 In column C the difierence, or the amount absorbed by the 



plant. 



Phosphoric Acid. 



