261 
THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, August 2, 1859. 
THE SCIENCE OF GARDENING. 
(Continued from page 241.) 
Salts of Ammonia.— These, without any exception, are 
powerful manures, though varying in their amounts of benefit to 
the crops for the increase of which they are applied. More than 
thirty years since wc pointed out that dung-manures are good fer¬ 
tilisers in proportion to the amount of ammonia they contain, : 
and we endeavoured to account for it upon the known stimulating j 
properties of ammonia. There was, also, the known fact, that 
such highly ammoniated dung-manures decompose and become 
soluble more rapidly than other organic manures containing less 
ammonia. Since then, chemical analysis has shown that azote, 
or nitrogen, a chief constituent of ammonia, is also a constituent 
of vegetables more prevalent than had been ascertained at the 
time we wrote. 
The pungent smell in stables, and which arises from the fer¬ 
menting dung of hotbeds, is caused by the ammonia which is 
escaping. To prevent this escape, it is not unusual to sprinkle 
powdered gypsum (sulphate of lime), among the dung and over 
the pavement of stables. Gypsum spread over a soil at the time 
dung is dug in also prevents the escape from it of the ammonia. 
It is then spoken of as fixing the ammonia. 
This process consists in the combination of the sulphuric acid 
of the sulphate of lime with the ammonia, and the consequent 
formation of sulphate of ammonia, a salt which is said to be thus 
fixed in the soil, because it is not volatile, or vaporised in a tem¬ 
perature in which several other of the salts of ammonia are com¬ 
pletely removed from the soil. This salt, in common with other 
salts of ammonia, is a powerful fertiliser, and is one of those 
valuable additions to the list of the cultivator’s agents for which 
he is indebted to modern chemistry. Ammonia consists of 
hydrogen seventy-four per cent., nitrogen or azote twenty-six per 
cent. The following is the composition of its three chief salts, 
which are easily purchaseable :— 
Acid. Ammonia. Water. 
Sulphate . . . 54.66 ... 14.24 ... 31.10 
Carbonate . . . 45.00 ... 43.00 ... 12.00 
Muriate . . . 49.55 ... 31.95 ... 18.50 
In 1840, Liebig, when speaking of the source from whence 
plants obtain the greatest portion of nitrogen, combated pretty 
successfully the old opinion that they derived it chiefly from the 
atmosphere. He remarked (Organic Chemistry, p. 69), “ We 
cannot suppose that a plant would attain maturity, even in the 
richest mould, without the presence of matter containing nitro¬ 
gen, siuce wo know that nitrogen exists in every part of the 
vegetable structure. The first and most important question to be 
solved therefore is, How, and in what form, does Nature furnish 
nitrogen to vegetable albumen, and gluten to fruits and seeds ? ” 
After giving a variety of facts in support of the opinion that it is 
ammonia which affords all vegetables, without exception, the 
nitrogen which enters into the composition of their constituent 
substances, he adds the way in which plants supply themselves 
with ammonia :—“ The nitrogen of putrefied animals is contained 
in the atmosphere, as ammonia, in the form of a gas which is 
capable of entering into combination with carbonic acid gas, and 
forming a volatile salt. Ammonia hi its gaseous form, as well as 
all its volatile compounds, is of extreme solubility in w'ater ; am¬ 
monia, therefore, cannot remain long in the atmosphere, as every 
shower of rain must condense it and convey it to the surface of 
the earth. Hence, also, rain water must at all times contain 
ammonia, though not always in equal quantity. It must be 
greater in summer than in spring or in winter, because the in¬ 
tervals of time between the showers are greater ; and when several 
i wet days occur the rain of the first must contain more of it than 
of the second. The rain of a thunder-storm, therefore, after a 
long protracted drought, ought, for this reason, to contain the 
greatest quantity which is conveyed to the earth at one time. But 
all the analyses of atmospheric air hitherto made have failed to 
demonstrate the presence of ammonia; although, according to 
our view,” says M. Liebig, “ it can never be absent. Experiments 
made in the laboratory of Giessen, with the greatest care and 
exactness, have placed,” continues Liebig, “ the presence of 
ammonia in rain water beyond all doubt. It had hitherto 
escaped observation, because no one thought of searching for it. 
All the rain water employed in this inquiry was collected 600 paces 
south-west of Giessen, whilst the wind was blowing in the direction 
of the town. When several hundred pounds of it were distilled 
in a copper still, and the first two or three pounds evaporated, 
with the addition of a little muriatic acid, a very distinct crystalli¬ 
sation of sal ammoniac was obtained. The crystals had always 
a brown or a yellow oolour. Ammonia may also always be 
detected in snow water. Crystals of sal ammoniac were obtained 
by evaporating in a vessel with muriatic acid several pounds of 
snow, which were gathered from the surface of the ground in 
March, when the snow had a depth of ten inches. The inferior 
layers of snow which rested upon the ground contained a quantity 
decidedly greater than those which formed the surface. It is 
worthy of observation, that the ammonia contained in rain and 
snow water possessed an offensive smell of perspiration and 
animal excrements, a fact which leaves no doubt respecting its 
origin. The products of the distillation of flowers, herbs, and 
roots, with water, -and all extracts of plants made for medicinal 
purposes, contain ammonia. The unripe transparent and gela¬ 
tinous pulp of the Almond and Peach emit much ammonia when 
treated with alkalies. The water which exudes from a cut Yinc, 
i when evaporated with a few drops of muriatic acid, also yields a 
gummy deliquescent mass, which evolves much ammonia on the 
addition of lime. Ammonia exists in every part of plants, in the 
roots (as in Beet-root), in the stem (of the Maple tree), and in 
! all blossoms, and fruit in an unripe condition. Putrid urine is 
employed in Flanders as a manure with the best results. During 
the putrefaction of urine, ammoniacal salts are formed in largo 
quantity, it may be said exclusively ; for, under the influence of 
heat and moisture, urea, the most prominent ingredient of (he 
urine, is converted into carbonate of ammonia.” 
“‘Ammonia,’ ” says Professor Johnston (Elem. of Chemistry , 
p. 22), “ ‘ is naturally formed during the decay of vegetable sub- 
I stances in the soil. This happens either, as in animal bodies, by 
the direct union of nitrogen with a portion of the hydrogen of 
which they consist, or by a combination of a portion of their 
hydrogen with the nitrogen of the air; or, when they decompose, 
in contact with air and water j at the same time, by their taking 
the oxygen of a quantity of the water, and disposing its hydrogen 
at the moment of liberation to combine with the nitrogefl of the 
air, and form ammonia. In the two latter modes, ammonia is 
formed most abundantly when the oxygen of the air does not gain 
the readiest access. Hence, in open subsoils in which vegetable 
matter abounds, it is most likely to be produced ; and thus one of 
the benefits which follow from thorough draining and subsoil 
ploughing is, that the roots penetrate and fill the subsoil with 
vegetable matter, which, by its decay in the confined atmosphere 
of the subsoil, gives rise to this production of ammonia.’ ”— 
(C. Johnson's Modern Agricultural Improvements.) 
That the salts of ammonia are very powerful manures has been 
established by the experience of many practical men ; and whether 
applied in the form either of gas ammoniacal liquor or sulphate 
of ammonia, they have been found to benefit very largely Potatoes, 
Asparagus, Peas, Turnips, Fuchsias, Pelargoniums, and Iloly- 
I hocks. We believe that there are few, if any, plants cultivated 
! in our gardens that would not be benefited by these ammoniacal 
| applications, care being taken not to apply them too liberally. 
Half an ounce of sulphate of ammonia to a gallon of water is 
quite enough.—J. 
(To he continued.) 
A NOTE-WORTHY APPLE TREE. 
As I was taking a stroll on the 4th of April last among my 
neighbours’ gardens, to my great surprise I saw fruit on an Apple 
tree, apparently. It is not less than thirty years old, and is one 
of the largest trained trees that I ever saw. It stands on a south¬ 
west aspect, planted against a farm-house, with its stem to the flue, 
where the fire is burning winter and summer. It is growing in 
rather a strong soil, with its roots feeding in a well-kept flower 
garden, which is not to be often met with at many farm-houses. 
| Now, this wonderful tree had not less than two dozen fine 
Keswick-Codlin-like Apples on, which had been left on the tree 
to stand the winter. They had over them a thin piece of calico 
to protect them from severe frosts, and the rest of the crop had 
been gathered off the tree last October and stored. My friend 
gave me four of them ; and I asked him to allow me to see if 
those left on the tree were tied on, and, to my astonishment, I 
found that they required no tying, and found them as Nature 
had placed them. 1 took hold of one, and thought it would not 
require much pressure to get it off, but I wa3 very much mis¬ 
taken ; it was so very firm that I was afraid that I should pluck 
off the spur if I had not taken hold with the other hand. I cut 
the Apple in two. It was as we see a Keswick Codlin when cut 
on the 1st day of November, and had a most excellent flavour. 
