FLORIDA STATE HORTICULTURAL SOCIETY. 
85 
and opening up of new countries and the 
discoveries of great deposits of valuable 
mineral material, has supplied everything 
needed with a lavish hand. Nor has man 
been at all backward in using, with the 
greatest freedom and often times with 
the most inexcusable wastefulness, the 
resources which have been so bountifully 
given to him. The time has already ar¬ 
rived, however, when we begin to look 
into the future and speculate as to what 
is going to happen to posterity when we 
shall have exhausted the resources which 
we are now drawing on with ever-increas¬ 
ing freedom to supply the constantly 
growing demands. That the crude ma¬ 
terial stored in the earth, which has 
grown to be so indispensable to our wel¬ 
fare, will eventually be exhausted, no one 
can doubt, and in fact it is possible to 
calculate approximately, with the present 
rate of use, when many of our natural 
resources will be exhausted, a period in 
many instances surprisingly and almost 
alarmingly short. We must then, con¬ 
sole ourselves with the above mentioned 
fact, that some discovery will be made 
which will enable us to get along as well 
or better without them. 
Let us consider for a moment, the sit¬ 
uation in regard to the future supply of 
fertilizing matei:ials and see what is being 
done to provide for the time when we 
shall have exhausted the great deposits 
that have proved of such inestimable val¬ 
ue to agriculture. First in regard to pK)t- 
ash. It is calculated that the present con¬ 
sumption of potash, for all purposes, is 
over three million tons a year and that it 
is constantly growing. Practically all of 
this comes from the great Stassfurt de¬ 
posits in Germany. As minor sources of 
supply we have wood ashes and cotton 
seed hull ashes, which are limited. About 
2000 tons of muriate of potash are an¬ 
nually made in the south of France from 
sea water and the Scottish manufacture 
of kelp yields perhaps 1000 to 1200 tons 
yearly as a by-product. There are a few 
other minor sources of supply, such as ni¬ 
trate of potash, wool washings and beet 
sugar residues. Leaving out these minor 
sources, which supply but a very small 
part of the total demand, we have as prac¬ 
tically the sole source, the great potash 
deposits at Strassfurt, Germany. Al¬ 
though the yearly output of this great 
collection of mines is now nearly four 
million tons a year and is steadily in¬ 
creasing, the supply seems almost inex¬ 
haustible, so that it will at least be many, 
many years before mankind will find it¬ 
self face to face with the problem of its 
potash supply, which has become so es¬ 
sential to successful agriculture, and the 
necessity for which will grow greater as 
the population increases, virgin soils are 
robbed of their natural fertility, and in¬ 
tensive farming becomes more and more 
a necessity. Let us hope that when that 
times comes, some means will have been 
found or new discoveries made, which 
will supply the deficiency. 
In regard to phosphoric acid the natur¬ 
al supplies may be summed up in general, 
in the deposits of phosphate rock, phos- 
phatic guanos, bones and slag. The great 
guano deposits which have been drawn 
upon so heavily in the past will be ex¬ 
hausted before a great many years, and 
although smaller gauno islands may from 
time to time be discovered, the supply 
from this source must gradually diminish. 
The conditions which allow the accumu¬ 
lation of such deposits, which require 
many years to form will probably never 
