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-wooa, 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,), 
the latter being taken as unity. 
POs N. 
In 7 Samples of Rye-kernel Fehling & Faiszt found the ratio of - 
PO; toN to range from......1 : 1.97—38.06 
do 11 do do do Mayer do do do 1: 2.04—2.38 
do 5 do do do Bibra do do do 1: 1.68—2.81 
do 6 do do do Siegert do do do 1: 2.35—2.96 
do 28 do do do the extreme range was from........... 1: 1.68—8.06 
do 2 do of Wheat-kernel Fehling & Faiszt found the ratio of 
PO; to N to range from....... 1: 2.71—2.86 
do 11 go” ao) “de Mayer do do do 1: 1.838—2.19 
do 2 do do do Zoeller do do do 1 : 2.02—2 16 
do# do do do Bibra do do do 1: 1.87—3.55 
do 6 do do _ do Siegert do do do 1: 2.80—3.33 
dobli do do do the extreme range was from.......... 1: 183-355 
