114 
FLORIDA STATE HORTICULTURAL SOCIETY. 
liked by the citrus grower because this 
magnesia acts readily as a base and aids 
in sweetening the land. Muriate of pot¬ 
ash is the richest of the potash salts, but 
because of its chlorine content cannot be 
used on certain crops. It is especially un¬ 
desirable for citrus trees and tobacco. 
Ivainit has even more chlorine, part of 
which is in combination with sodium, 
making about one-third of kainit our or¬ 
dinary salt. This is quite effective in 
vegetable raising for driving away in¬ 
sects and some fungous troubles, but for 
many crops would need to be applied at 
least a month before planting or it would 
“burn” the plants. 
Thus we have much to think about 
when trying to supply food to vegetation 
just what sources—just what propor¬ 
tion each of the different forms of am¬ 
monia used should make of the whole am¬ 
monia content, that there be no lack, no 
waste,—just how much phosphoric acid 
and potash to put with this ammonia to 
give exact balance to this particular crop. 
It is a long, long lesson and one that must 
be worked out in the field; but when it 
comes to mixing these ingredients, how 
many times does the lack of chemical 
knowledge cause great loss! I know, 
personally, one prominent gardener who 
mixes ashes with his fertilizer and chuck¬ 
les as he smells the escaping ammonia, 
because the mixture is “so strong .” It 
has often seemed to me that one of the 
wisest sayings I ever heard in regard to 
home mixing of fertilizer was: “The man 
who knows enough to mix his fertilizer, 
generally knows enough not to” 
Let us for a closing paragraph briefly 
note the course of the plant food after it 
enters the plant. It is absorbed through 
cell walls as through the walls of the 
rootlets and passes from cell to cell up¬ 
ward, remaining the same crude sap, in¬ 
capable of nourishing the plant, until it 
reaches the leaves. There it is “digested” 
and becomes “elaborated” sap capable of 
forming live substance, first in the veg¬ 
etable kingdom and then on to animal 
matter. This change can take place only 
in those portions of the plant which are 
green in color, being the result of the 
combined action of chlorophyll and sun¬ 
light. Chlorophyll is the green substance 
in leaves, young twigs and immature fruit 
and while absolutely necessary to higher 
plant life, is powerless to act except un¬ 
der the influence of the sun. All growers 
appreciate the value of color in the leaf, 
but many fail to realize the great impor¬ 
tance of abundant foliage and of giving 
sunlight free access to same. Dense 
growth encourages disease as well as in¬ 
sects. 
From the leaves, the elaborated sap 
goes by way of the inner bark to supply 
the various needs of the plant. 
Three questions naturally arise: Why 
does the soil moisture enter the plant? 
Why does it work upward? How is it 
that the right materials are carried to the 
right places to supply the plant’s needs, 
if these materials are at hand, and after 
the need of a certain substance is supplied, 
generally speaking, the roots take up no 
more of that substance, however plenti¬ 
fully it may lie around them? 
The first is answered by the fact that 
the soil water is less heavily laden with 
plant food than the plant’s juices ~o it 
pushes its way into the cells. The up- 
