110 
JOURNAL OF HORTICUL'l URE AND COTTAGE GARDENER. 
[ August 9, 1883. 
the same pot. But we can do better: we can repot them 
and give them fresh soil, which acts like a charm. Not at 
the usual time, though. Some good man invented repotting 
in spring after the growth had started, and everybody know¬ 
ing the doer to be successful have unquestionably followed. 
But that was before root-pruning was understood. Why it 
i3 the right thing to root-prune fruit trees in autumn and 
flowering shrubs in pots in spring we cannot guess. Perhaps 
Apples and Pears would be better root-pruned after the 
growths are started in spring, but we do not know, never 
having tried. But we know it gives Fuchsias a great check. 
Fuchsias grown in the liberal way here recommended 
require a check in October. A proper drying-up accomplishes 
this, or a touch of frost will do it; the frost is dangerous ; 
the drying gives a check that weakens much. It is successful, 
though. The sap goes out of the branches, they are pruned, 
and in a month or two push again, though very weakly. 
The drying killed the roots, and only slowly the plants re¬ 
cover. But they are in that way when they are shaken out 
of their pots root-pruned and repotted. A check follows a 
check, both unnatural, dead branches, feeble growths, and 
eyesores being the result. 
A better way is in autumn to pinch all growing shoots, 
then a week after to turn the plants out of the pots, reduce 
the balls, and repot. The soil is kept moderately moist. 
Under this treatment the tops grow no more. The leaves, 
instead of falling desiccated and dried to death, ripen off, 
deliver their essence to the stems, which, instead of being 
sent to rest unprovided with a store to start the plant in 
spring, is stored full. The roots, instead of being dead, 
grow into the new soil, and in thus growing take off the surplus 
energy of a plant eager to advance. Such a plant not only 
starts with very much greater energy in spring, but gets no 
check afterwards, and instead of dead shoots and paltry 
growths becomes a huge shrub or small tree. 
Space forbids particulars about pruning, training, and 
routine treatment. But we have pointed out the points 
where would-be Fuchsia growers err. The soil, potting, feed¬ 
ing, repotting, and root-pruning are the salient points, and 
when these are rightly attended to training and pruning are 
secondary points that the judgment alone can guide in.— 
Cultivator. 
GARDEN CHEMISTRY. 
(Continued from, page 89.) 
THE SOURCES AND USE OF NITROGEN. 
Being composed of exactly what garden plants most demand— 
nitrogen and phosphorus—what garden soils are deficient in, as well 
as other fertilising matter, guano when good is perhaps the best 
natural-artificial, if the term be allowed, in the market. For most 
garden crops it is very specially suited. For Vines and other fruit 
trees needing assistance it has been proved of extreme value. 
Nothing better exists for Cabbages, for ordinary flower beds, or top¬ 
dressing grass plots of all kinds, from the close-shaven bowling green 
to the pasture field. 
Nitrate of soda (sodic nitrate) furnishes nitrogen to plants in a 
very concentrated form. Some samples are very impure, often, but 
not always, the result of being adulterated with common salt. Even 
“pure’' samples contain from 3 to 4 per cent, of foreign matter. 
The nitrogen in nitrate of soda exists to the extent of 15 or 1G per 
cent., so it will be seen that it takes nearly 3 lbs. of it to be equal to 
2 lbs. of sulphate of ammonia. 
Except in the case of the Lcguminosie this salt has a telling 
effect on vegetation, especially on poor land. Wherever nitrogen 
is wanted it may be applied, but only in summer or spring. In wet 
seasons it is inferior to sulphate of ammonia, very probably because 
it is very easily washed beyond the reach of the roots and away 
altogether ; but in seasons of drought it is better than ammonia salts, 
which remain on the surface unchanged. Some agricultural chemists 
consider that its presence fa ours the utilisation of phosphates by 
rendering the latter more soluble ; but it may as reasonably be 
supposed to favour their absorption by giving "the plants greater 
power to attack them. 
It makes a good liquid manure, but as it affords nothing but 
nitrogen it will not long sustain the vigour it creates unless other 
essentials are applied. When dissolved in water the temperature of 
the ’alter is rapidly lowered. This should be borne in mind, for the 
cold may often do mischief when the water is applied to plants in a 
high temperature. 
Ammonia is familiar to most persons as smelling salts—ammonia 
carbonate. In this form it is said to be effective as an insecticide 
when diluted in water. An ounce of it is sufficient for a gallon of 
water. While it is death to green fly in Roses, it promotes their 
luxuriance. According to Professor Johnston a piece of it laid on a 
plate in a plant house evaporates slowly, and “ adds greatly to the 
green and healthy appearance of the plants.” 
It is chiefly in the form of the sulphate that ammonia is to be had. 
This is manufactured from gas liquor—till lately a “ waste product.” 
Unlike the nitric acid of sodic nitrate, it is not readily washed from 
the soil, hence it is more valuable in wet districts or seasons ; but, 
before being used, it changes to nitric acid and is then easily lost. 
The sulphate is generally to be had nearly pure, when it contains 
from 23 to 25 per cent, of nitrogen. Sometimes a small quantity of 
ammonic sulphocyanide is present, and as this is very injurious its 
presence should be sought for. If a solution in water turns blood 
red on the addition of a little ferric chloride (Fe^ Clg) the sulpho¬ 
cyanide is present. 
Sal-ammoniac (ammonic chloride) is occasional^ used, and is a 
very powerful manure, containing, as it does, 31-78 of ammonia when 
pure ; this and the preceding salt have solvent powers on phosphates. 
Some have thought that steeping seeds in solutions of ammonia salts 
hastened their germination and added vigour to the resulting plants. 
Wheat has been benefited this way ; but with ordinary garden seeds 
the reverse is the case, or the writer has been unfortunate in his 
experimenting. 
Ammonia salts may be applied to everything for which nitrate 
of soda is suitable, and is even better for making liquid manure than 
the latter. It has no smell, and may therefore be used in houses 
where evil-smelling compounds would not be tolerated. 
Nitrogen exists in a great many substances which are employed 
for manure, but which we need only name here. Flesh has been 
employed in gardens as manure, but not often, and will be even less 
in the future. Oftener fish has been likewise employed near the sea, 
when over-abundance has been landed. For the grosser-growing 
vegetables it proves effective. Soot owes its efficacy as a manure to 
ammonia, and while it is also a deterrent on worms and other insects, 
is often thrown away. Seaweeds are rich in nitrogenous matter, and 
are valued for manure whenever they can be had. In East Lothian, 
according to Johnston, 16 cwts. are considered equal to 20 of 
ordinary manure, and in the western Highlands are considered of 
double value. In Fife Clover is said never to fail after the appli¬ 
cation of seaweeds, but whether this is owing to any peculiarity in 
the way the nitrogen is combined or to the potash they contain is 
not clear. As most seaweeds contain much sulphur, possibly that 
may help Clover ; and if so, the effect on Peas and Beans should 
prove similar. Brewers’ grains, malt dust, chaff, and bran have all 
been used as manure, and are valuable chiefly because of the nitrogen 
they contain ; but, unless damaged, they may be much more econo¬ 
mically employed for feeding animals. Rape, hemp, poppy, cotton, 
and cocoa-nut, cakes are oftener employed, but more by the farmer 
than the gardener. Blood dried and ground to powder is a manure 
containing nitrogen equal to from 12 to 16 per cent, of ammonia. 
Blood may be made into compost with soil or ordinary manure ; it 
is a powerful stimulant. Horn dust is a capital article for mixing 
with potting soils or for fruit trees. Buffalo horn shavings were 
introduced a few years ago. We seldom hear of them now. Ordi¬ 
nary horn dust contains from 15 to 17 per cent, of ammonia (nitrogen 
equal to). 
While the soil gains nitrogen from the rain, the rain also is the 
cause of heavy loss, more especially on heavily manured ground, such 
as that of gardens, in localities where the rainfall is great. At 
Rothamsted nitrates equal to fully 40 lbs. of nitrogen per acre 
appeared in the drainage from a bare unmanured fallow. This was 
the average of five years, and is equal, or very nearly so, to what is 
removed in 30 bushels of Wheat. Garden soil contains much more 
nitrogen than ordinary field soil ; and though it is hardly likely, 
ground, even though rich, when under crop will lose as much from 
this cause as fallow soil does, still there is hardly room to admit a doubt 
that the loss is very considerable. 
Ammonia is not subject to being washed away as is nitric acid, 
neither is nitrogen in an organised form ; but in the soil these are 
speedily converted by an invisible bacterium into nitrates. This 
transformation proceeds rapidly or slowly according to the heat in 
the soil. In winter it goes on slowly, in summer rapidly. While 
at Rothampsted some 6 lbs. appeared in the drainage during the 
quarter beginning April and ending in June, in October to December 
no less than 15 lbs. were lost. In summer the growing plants utilise 
the nitrates as fast as they are formed ; but when in autumn the 
cmps are removed the rapidly forming nitrates are at the mercy o£ 
the rain which passes through the soil. It was till lately supposed 
