380 STATE BOARD OF AGRICULTURE. 



HISTORY. 



Dr. Priestley was the first person to experiment upon the influence exerted 

 by a plant, during active growth, upon the air surrounding it, and he camo to 

 the conclusion that a certain small amount of atmospheric nitrogen was taken 

 up by the plant. Ingenhouz agreed with Priestley that plants, during active 

 growth, took a certain quantity of nitrogen from the air and combined it into 

 plant tissue. Seunebier and Woodhouse, from their experiments, came to the 

 opposite conclusion, that plants are incapable of fixing in organic form free 

 nitrogen. DeSaussure made careful investigations, and concluded that plants 

 not only did not take up free nitrogen, but on the other hand, they gave off 

 nitrogen during active growth. 



The subject was left without further experimental investigation for nearly 

 thirty years, when Boussingault, in 1837, began his careful and exhaustive 

 investigations, which were carried on for many years. He came to the con- 

 clusion that plants do not derive any of their nitrogen from the free nitrogen 

 of air, or from uncombined nitrogen dissolved in water. 



In 1849, Ville, of Paris, objected to Boussingault' s method of experiment- 

 ing, that plants could not make a normal growth in such a confined body of 

 air as that contained in a glass bottle or globe. He repeated Boussingault' s 

 experiments, but used a room glazed with glass in place of a glass globe, and 

 announced as the result, that while cereals produced a crop containing only 

 two or three times as much nitrogen as was contained in the seed from which 

 they grew, cress, sunflower, and colza produced in the crop 25 to 40 times as 

 much nitrogen as was contained in the seed. Ville, therefore, announced as 

 the result of his experiments, that while certain kinds of plants have little or 

 no power of taking up free nitrogen, other kinds of plants have the power of 

 combining with free nitrogen and using it in building up their azotized tissues. 



Such contradictory results reached by two such distinguished scientists provoked 

 a lively discussion, and, in the interests of harmony, and to establish scientific 

 truth, a commission was appointed by the French Academy, with such eminent 

 scientific names as Dumas, Regnault, Payeu, Decaisne, Peligot, and Ohevreul, 

 to repeat the experiments of Ville and report the results to the Academy. 

 The experiments were made at the Museum of Natural History in Jardin des 

 Plantes in 1854. Some accidents in the course of the experiments threw diffi- 

 culties in the way of reaching the fullest results desirable, but the commission 

 found evidence of some gain of nitrogen during the growth of the plants, and 

 finally made this report: '*That the experiment made at the Museum of 

 Natural History by M. Ville is consistent with the conclusions which he has 

 drawn from his previous labors." Not a very hearty endorsement. 



Other French experimenters entered the field about tlie same time, and the 

 general results at which they arrived were adverse to the conclusions of M. 

 Ville. 



ENGLISH EXPERIIIENTS. 



In 1857, '58, and '59, Lawes, Gilbert, and Pugh carried out an extended and 

 most carefully conducted set of experiments at Rothamsted, in which every 

 conceivable source of combined nitrogen beyond the known amount contained 

 in the seed was excluded ; the soil, the containing vessels, the water and the 

 air admitted to the plant were deprived of every trace of combined nitrogen. 

 The plants were supplied with every substance required for complete growth 

 except combined nitrogen, while an abundant supply of free nitrogen was fur- 

 nished in the air surrounding the plant and dissolved in the water used during 



