245 



THE FORM IX WHICH THE MINERAL ELEMENTS EXIST IN THE I'LAXT. 



If we take a living tree, whose ashes are rich in carbonates of potash, 

 and test its sap, we find instead of the usual alkaline reaction of the salts 

 a strong acid reaction, due to the presence of vegetable acids — oxalic, 

 tartaric, citric or malic, so united with the alkaline potash as to form 

 an acid salt which is held in solution in the sap of the tree. Combustion 

 converts the vegetable acids into carbon dioxide, and the latter unites 

 with the bases. 



HOW HAVE THESE SIISSTAXCES J5EEX ASSIMILATED BY THE TREE? 



It must be remembered that the sap of the tree is charged with carbon 

 dioxide and often sodium chloride, therefore the double silicates of am- 

 monia and aluminum in the soil, which are somewhat soluble in such 

 water, are furnished to the tree in sutticient quantities for its development. 

 The silicates of iron are decomposed at ordinary temperature by carbon 

 dioxide. They are, therefore, made soluble in water charged with carbon 

 dioxide and exist in solution in the sap. The alkaline carbonates also 

 bring about many decompositions in the mineral matter of the soil. It is 

 by the introduction of atmospheric oxygen that many of the compounds 

 entering into the double silcates of aluminum are gradually decomposed, 

 and the alkalies — potash, soda and lime, are rendered capable of assimila- 

 tion and pass in solution in the sap of the tree. 



The relative proportion of the constituents of the ash of trees is found 

 to vary in diflFerent trees, and also in different parts of the same tree. 

 The following analyses were made of the ash of the young and thrifty 

 shoots which represent a fair average of the proportion of the mineral 

 constituents of the soil that are assimilated by the tree in a year's growth: 



No. 1— Pear, Duchess 



No. 2 — Pear, Anjou j 



No. 3— Pear, Sickles | 



No. 4— Pear, Bartlett 



No. 5— Pear, Duchess 



No. fl— Pear, Vicar of Wakefield 



No. 7— Pear, Howell 



No. 8— Plum, Lombard . . . 

 No. 9— Plum, Lombard . . . 

 No. 10— Plum, Lombard Roots 

 No. 11— Peaeh, Late Crawford 



No. 12— Osage, Orange 



No 13— Cherrj-, Winslow . . . 



.40 

 4 45 

 .97 



2.71 



9 60 



trace. 



10.74 



4 01 



trace. 



Cl'dsbyditt' 



15.78 



30.96 

 26 93 

 25 45 

 29.99 

 a5.89 

 37.98 



No. 14— Cherry, May Drake . 

 No. ]. 5— Cherry Wood .... 



No. 16— Cherry Bark 

 No. 17— Apple tree . 



31.02 

 24.43 

 31.39 

 2 19 

 34.78 



Cl" 



..iO 

 20.8 



12.43 

 3.86 

 4.45 

 17.34 

 11.00 



14.5 



KaCl.5 

 Na„0.5 



98.52 

 97.31 



99.81 

 98.47 

 98.76 

 100.41 



100.00 

 98.27 

 99.17 

 99.32 



100.09 

 99.41 



NaCI 

 .6 



