FLORIDA .STATE HORTICULTURAL SOCIETY. 
113 
in both ingredients we have a mono-cal¬ 
cium phosphate and a sulphate of lime. 
The same form of plant food is in each, 
but it is accompanied by a little more sul¬ 
phate of lime in the acid phosphate than 
in the dissolved bone. This sulphate of 
lime is really no plant food, but it has a 
wonderful influence on the crops because 
of the chemical changes caused by its 
presence in the soil, through which much 
latent plant food becomes available. Such 
an agent is termed a “catalyzer” and it 
is now generally recognized that phospho¬ 
ric acid is also a great catalyzer, and that 
it well pays to apply far more than is ac¬ 
tually needed by the plant, because of 
this quality. Another effect of a large 
phosphoric content is a tendency to has¬ 
ten maturity. This is a detriment in the 
raising of some crops, beans and celery, 
for instance, but the citrus grower who 
wishes to avail himself of the advantages 
of an early market finds this fact of great 
value.' 
Basic slag is another source of phos¬ 
phoric acid. It is very slow acting and 
its value is still undetermined. 
Peruvian guano is called a phosphatic 
fertilizer, but contains some of all four 
essentials. Though of organic origin, it 
cannot be classed as an organic fertilizer, 
really, for its condition is such that al¬ 
though it has all the virtues of organic 
matter it has none of the evils, therefore 
it can be used in citrus culture. Indeed, 
under some circumstances and when re¬ 
enforced with the correct proportions of 
the proper chemicals, it stands pre-emi¬ 
nent. 
We have given considerable force to 
the word available because in both am- 
moniates and phosphatic goods, the “plant 
food” is so likely to be useless to the plant. 
When there is an abundance of unavaila¬ 
ble plant food in even the poorest soils, 
why add more? The value in applied fer¬ 
tilizer is in its quick results . If we have to 
wait until the next year or the next gen¬ 
eration to get returns for the money in¬ 
vested this year we are losing the use of 
our money, for there is only the plant 
food we have paid for and the longer it 
stays in the soil the longer our money is 
locked up. Some people have expatiated 
upon the effects shown in after years. A 
certain amount of plant food will produce 
only certain results and the longer it takes 
for it to produce these results, the more 
time there is for wastes through drainage, 
etc. A grower should build up the text¬ 
ure of his soil by proper tillage and the 
addition of humus, but Nature has fore¬ 
stalled him in furnishing unavailable 
plant foods. 
All our potashes are water soluble and 
in the same form whether from organic 
sources, ashes, or from the different pot¬ 
ash salts—nitrate, sulphates, muriate or 
kainit. They differ only as to their sur¬ 
roundings. The organic source used is 
pulverized tobacco stems and the one 
drawback is the extreme high cost. This 
precludes its general use. The potash in 
ashes also costs so high that ashes are in¬ 
variably bought because of other qualities 
and not for their potash content. We have 
already taken up nitrate of potash under 
the nitrates, and dealt with sulphate of 
potash under our talk about acids. We 
would mention, however, that the low 
grade sulphate of potash contains a large 
percentage of sulphate of magnesia and is 
