FLORIDA STATE HORTICULTURAL SOCIETY. 
71 
considerable time and the alcoholic fer¬ 
mentation and carbondioxide evolution 
determined. In this connection I wish to 
call attention to the probable reason of 
sulphate of ammonia being a healthful 
stimulus to the enzymes of oranges that 
sweeten the fruit by quoting frbm “the 
chemical nature of diastase.” T. B. Os¬ 
borne, (E. S. R. No. 3,1895. page 182.) 
The method used for preparing the en¬ 
zyme which differs from the one usually 
employed was to “first separate the pro- 
teids from the carbohydrates and other 
soluble substances by saturating the ex¬ 
tract with ammonium sulphate, thereby 
precipitating the ferment and proteid's to¬ 
gether ; next to remove this proteid exist¬ 
ing as globulin by dialysis; and then if 
possible to separate the albumin and pro- 
teids by fractional precipitation with al¬ 
cohol. In following this method a meas¬ 
ured quantity of malt extract was saturat¬ 
ed with ammonium sulphate, the precipi¬ 
tated proteid matter was filtered out, dis¬ 
solved in water and the clean filtered solu¬ 
tion made up to value of the original ex¬ 
tract. This solution was found to have the 
same diastatic power as before precipita¬ 
tion, thus showing that ammonium sul¬ 
phate had not injured the diastase.” 
I would further call attention to a fact 
I have often mentioned by quoting an ex¬ 
tract from a report of work by G. Lieb- 
sc'her, (E. S. R., Vol. 7, No. 8,1896, page 
665,) “as regards the contents of phos¬ 
phoric acid it appears that the solubility 
is of more significance than the total 
amount present. With a high content of 
of sesquioxides a soil will show great need 
of phosphatic fertilizers, although it al¬ 
ready contains a high per cent, of phos¬ 
phoric acid.” 
As a citrate solution is generally used 
in analyses to determine the percentage of 
reverted phosphoric acid it would seem 
orange trees ought to have greater pow¬ 
ers of assimilation of phosphoric acid 
than other plants. 
Experiments by P. Kassovich (E. S. 
R. XVI, No. 2,1048, July, ’05,) show 
that the amount of carbon dioxide set 
free 'by the roots was about twenty times 
greater than would have been required to 
render soluble all the phosphoric acid as¬ 
similated by the plants if it were supplied 
in an insoluble form. Still further, A. 
Quartarali (E. S. R. XVII, No. 5,449, 
Jan. ’06, shows “That the organic acids 
which usually occur in plants first render 
insoluble phosphates soluble and then 
convert them into di-hydrogen phos¬ 
phates. Any free phosphoric acid which 
may be produced is converted in the plants 
into a di-hydrogen salt. This is explained 
by the lower acidity of organic acids as 
compared with phosphoric acid and by 
their greater affinity as compared with 
acid phosphates. 
D. N. Prianishni kov (E. S. R. XVI, 
No. 6,538) shows “that ammonium salts, 
especially ammonium sulphate, exert an 
important influence in rendering the phos¬ 
phoric acid of mineral phosphates avail¬ 
able to higher plants, while sodium nitrate 
exerts no such influence. For this reason 
ammonium sulphate is designated “Physi¬ 
ologically acid” and sodium nitrate “phy¬ 
siologically alkaline. A series of sand and 
water cultures with barley, oats, buck¬ 
wheat, flax, peas and vetches to determine 
the status of ammonium! nitrate with 
reference to acidity or alkalinity as thus, 
defined is reported. The results show that 
this salt is intermediate in its action be- 
