82 AGRICULTURAL EXPERIMENT STATION. [Jan. 



the plant is largely, if not exclusively, due to the presence 

 of acid combinations of oxalic acid with the alkalies, potassa 

 and soda. 



The soluble portion of the ash constituents contains the 

 subsequent substances in the following relative propor- 

 tions : — 



Per cent. 



Potassium oxide, 19.35 



Sodium oxide, . 10.79 



Calcium oxide, 47.53 



Magnesium oxide, 8.99 



Ferric oxide, 2.55 



Phosplioric acid, 10.79 



100.00 



The sudden appearance of this well-known plant upon 

 lands which, during the preceding season, had been free from 

 the objectionable weed, suggested the previously described 

 examination into its chemical composition. A more syste- 

 matic inquiry into the chemical character and the habits of 

 many of our weeds cannot fail to give us, here and there, 

 useful information reo-ardino; an intellio;ent course to lessen 

 their chances of a luxuriant growth. 



Good agricultural authorities in Europe state that this 

 vai'iety of sorrel does not grow upon a calcareous soil, but 

 thrives upon a sandy soil of a medium state of fertility. 

 They recommend a liberal application of lime or marl as an 

 effective remedy to check its growth. Judging from the 

 predominance of lime in the mineral constituents of the sor- 

 rel, as shown by the above analysis, it seems that the stated 

 beneficial action of lime and marl, if true, has to be ascribed 

 to their modifying influence on the physical and chemical 

 condition of the soil, and not to a deficiency of lime as a 

 special plant food. 



The material serving for our analysis grew upon a light, 

 sandy soil. 



