No. 4.] GERMAN EXPERIMENT STATIONS. 391 



that plants could appropriate atmospheric nitrogen ; l)ut 

 Sausseur in 1804 disproved Priestley's work. At the be- 

 ginning of this century Thaer observed that leguminous 

 crops seemed to leave the land in l)etter condition, and he 

 thought it very prol)able that the nitrogen was ol)tained 

 from the' air, and that it was set free from the roots in 

 the process of decay. Between 1830 and 1850 Monsieur 

 Boussingault made an exhaustive study of this sul)ject, and 

 finally came to the conclusion that plants could not utilize 

 the atmospheric nitrogen. Lawes and Gilbert, assisted by 

 Dr. Pugh, repeated these experiments very shortly after- 

 wards, and came to the same conclusion. Boussingault, 

 however, observed that, after his experiment })lats could 

 no longer produce a cro}) of grain by reason of their lack 

 of nitrogen, by growing leguminous cro})s for a year the 

 land became sufficiently improved to enable him to ()l)tain 

 another average grain crop. For example, he planted a 

 certain area of land with a ditierent crop each year during 

 five consecutive years, and removed each year the following 

 kiloo-rams of nitroo:en from the soil : — 



Lawes and Gilbert also confirmed these results, and both 

 French and Eno;li.sh investiirators concluded that it was not 

 necessary to apply nitrogen-containing manures to legumi- 

 nous crops, because these jJ^cints were enabled by their pene- 

 trating roots to dravj their supjiJ y from the lower strata of soil. 



Schulz-Lupitz, a very intelligent farmer of Saxony, 

 some ten years ago called attention to a large number 

 of experiments made by himself with leguminous crops. 



