202 HOW CROPS GROW. 



magnesia was present ; in that of Mont La Salle, it was ab- 

 sent. In the former existed but half as much carbonate 

 of potash as in the latter. In both, however, the same 

 total percentage of alkali and earthy carbonates was 

 found, and the amount of oxygen in these bases was the 

 same in both instances. 



Since the unlike but equivalent quantities of potash, lime, 

 and magnesia, contain the same quantity of oxygen, these 

 bases, in the case in question, do displace each other in 

 equivalent proportions. The same was true for the ash of 

 pine-wood, from Allevard and from Norway. On apply- 

 ing this principle to other cases it has, however, signally 

 failed. The fact that the plant can contain accidental or 

 unessential ingredients, renders it obvious that, however 

 truly such a law as that of Liebig may in any case apply 

 to those substances which are really concerned in the vital 

 actions, it will be impossible to read the law in the results 

 of analyses. 



Relation of Phosphates to Albuminoids, Liebig like- 

 wise considers that a definite relation must and does exist 

 between the phosphoric acid and the albuminoids of the 

 ripe grains. That this relation is not constant, is evident 

 from the following statement of the data, that have been 

 as yet obtained, bearing on the question. In the table, 

 the amount of nitrogen (N), representing the albuminoids 

 (see p. 108) found in various analyses of rye and wheat 

 grain, is compared with that of phosphoric acid (PO 5 ), 

 the latter being taken as unity. 



P0 5 N. 

 In 7 Samples of Rye-kernel Fehling & Faiszt found the ratio of 



PO 5 to N to range from 1 



do 11 do do do Mayer do do do 1 



do 5 do do do Bibra do do do 1 



do 6 do do do Siegert do do do 1 



do 28 do do do the extreme range was from 1 



do 2 do of Wheat-kernel Fehling & Faiszt found the ratio of 



PO 5 to N to range from 1 



do 11 do do do Mayer do do do 1 



do 2 do do do Zoeller do do do 1 



do 30 do do do Bibra do do do 1 



do 6 do do do Siegert do do do 1 



do 51 do do do the extreme range was from 1 



