106 
FLORIDA STATE HORTICULTURAL SOCIETY. 
upon the growth of most of our agricul¬ 
tural plants.” In another place, he adds: 
“the yields of the 38 miscellaneous crops 
show without exception, where no air- 
slaked lime was used, that the sulphate of 
ammonia was inferior in its action to the 
nitrate of soda, and in most cases proba¬ 
bly poisonous. On the other hand, where 
lime was applied in connection with the 
two forms of nitrogen, the ill effect of 
the sulphate of ammonia was not only 
overcome, but in the case of several 
crops the yield from the limed sulphate of 
ammonia plats even exceeded that where 
lime was used with the nitrate of soda.” 
He attributes the value of the lime to its 
overcoming the natural acidity of the soil 
and the acid tendency of sulphate of am¬ 
monia. Robert Warington, an English 
agricultural chemist, has made an ex¬ 
tended study of the comparative value of 
nitrate of soda and sulphate of ammonia, 
and he concludes among other things that 
on lands containing no carbonate of lime, 
sulphate of ammonia cannot be profitably 
used but nitrate of soda may be used. On 
lands containing a large amount of car¬ 
bonate of lime, sulphate of ammonia 
gives its best results when it has been 
plowed or harrowed in immediately aft¬ 
er it has been distributed. Loew has 
pointed out that acid compounds as su¬ 
per-phosphates, or acidity-producing com¬ 
pounds as sulphates should be avoided on 
acid soils, while alkalinity-producing com¬ 
pounds as nitrates should not be used on 
alkaline soils. 
These statements are not to be taken 
as arguments against the use of sulphate 
of ammonia, but as a plea for the more 
general use of carbonate of lime to cor¬ 
rect the natural acidity of the soil and 
the acidity which results from the con¬ 
tinued use of sulphate of ammonia. In 
some sections of the State the soils are 
just as much in need of having lime sup¬ 
plied, as they are of having phosphoric 
acid or potash. The State, is however, 
generously provided with the natural 
limestone rock; we have the mills for 
grinding it, and railroad facilities for 
transporting it; and if by failure to take 
advantage of such resources, we continue 
to limit the productivity of our soils and 
the efficiency of the fertilizers which we 
use at a great expense, we will have only 
ourselves to blame. 
SELECTIVE POWER OF PLANTS. 
Writers on Plant Physiology have call¬ 
ed attention to the fact that plants have 
the power of appropriating an acid and 
leaving the base, or of appropriating a 
base and leaving behind the acid with 
which it was combined. We thus speak 
of the basic or acid tendency of fertiliz¬ 
ing materials. Thus in the case of sul¬ 
phate of potash the plant undoubtedly 
uses more of the base, potash, that it 
does of the acid and we speak of this 
substance as acid in tendency. On the 
other hand, with nitrate of soda, the 
plant requires more of the acid radical or 
nitrogen than it does of the base, soda, 
and we speak of this as basic in tendency. 
In accordance with these principles 
Mayer has classified certain manurial 
substances according to the following 
groups: 
