118 THE LIFE OF A TREE. 
The soil contained a quantity of salt; and as 
these plants require a quantity of salt as part 
of their food, here they are to be found growing 
just as plentifully as if in their general position 
by the side of the restless sea-waves. It is 
worthy of particular notice that at this position— 
namely at Northwich—the plants are at least 
thirty or forty miles from the sea; and conse- 
quently their being found in this spot was en- 
tirely due to its containing that which forms part 
of their particular food. All around the district, 
the trees, shrubs, and plants were of the usual 
inland character ; but here, where a sea-side salt- 
ness existed, there was also a sea-side vegetation. 
We hope this little anecdote will both strongly 
impress the fact we are seeking to establish upon 
the reader’s mind, and that its import will be 
fully comprehended. A number of other in- 
stances of the attachment of plants and trees 
to particular sorts of soil could be mentioned ; 
but these are sufficient to illustrate the point in 
question,—which, we may be allowed to repeat, 
is, that besides carbonic acid, ammonia, and water 
from the air, plants both require and obtain 
various salt matters, and even earthy matters, in 
