SET OUT FRUIT TREES. 
335 
cultivation, as the moisture and vegetable mat¬ 
ter, the great mass is a silicate of alumina and 
alumina with iron. The earths, lime and mag¬ 
nesia, are never present in any large amount, 
and the saline matters are the residual salts of 
the rock not wholly washed out. The predom¬ 
inant ingredient is alumina, and as the charac¬ 
teristics of alumina are those of clay, they re¬ 
quire some consideration. 
Alumina attracts moisture; when very pure, 
it is kept dry with difficulty; when mixed with 
silica, forming porcelain and pottery clays, 
it is very retentive of water; such clays are 
made up of 40 of alumina and 46 of silica 
in 100 parts, and from their large amount of al¬ 
umina they are totally unfit for any agricultural 
purpose. The stiffest farming clay does not con¬ 
tain more than 25 per cent, of alumina, and is 
even then very difficult to work, owing to its 
affinity for water. In manufacturing pottery, it 
is difficult to get rid of this moisture, and the 
highest heat of a furnace is required to hake 
the clay; that is, free it completely from water. 
All soils containing clay exhibit the same pro¬ 
perty, so that a clayey soil means generally a soil 
imbued with moisture, stiff, cold, and heavy in 
its textural quality, This last sentence conveys 
the whole of its injurious effects, notwithstand¬ 
ing which, it has so many advantages that clay 
soil is universally preferred to any other. 
Alumina of itself is no nutriment to plants. 
It rarely, if ever, enters into the composition of a 
vegetable and appears rather to have been in¬ 
troduced accidentally than to be a necessary con¬ 
stituent of any vegetable growth. But it always 
supplies moisture to the plant, keeping the roots 
in a condition ever ready to absorb food, and 
constantly throwing out the spongioles; further¬ 
more, this water so supplied always contains 
saline matter, so that both moisture and salts 
are constantly supplied by a clayey soil. 
Alumina is the densest of the earths, and a 
clay is the heaviest of soils; if a cubic foot of 
loose earth weigh 95 lbs., a similar brick of 
clay will weigh 135 lbs.; there is more matter 
in a given space, and therefore more nourish¬ 
ment for plants in a given average of clay soils 
than in any other. 
Alumina has a great affinity for potash. It 
is almost impossible to wash it free from it, and 
clays have a similar property in retaining any 
potash salts in the ground. Perhaps this is the 
most valuable property of alumina. It may be 
said, with truth, that there is no stiff clay desti¬ 
tute of potash; and as this is the most important 
mineral ingredient in cultivated plants, we see 
one reason why clay soils are better adapted for 
husbandry than any other lands. 
Set out Fruit Trees. —As you value health, 
long life, and smiling friends, do not let the win¬ 
ter set in till this is done. If you cannot set 
set them out, get them home from the nursery, 
and bury the roots in garden mold and keep 
them till spring. Do not say you “ don’t know 
where to get them.” Send your orders to us, if 
you cannot do better, and we will see that you 
are supplied by an honest nurseryman. 
ECONOMY AND PRESERVATION OF FARMYARD 
MANURE. 
At a late meeting of the Highland and Agri¬ 
cultural Society of Scotland, Dr. Anderson de¬ 
livered an important lecture on the “ Economy 
of Manures,” from which we make the follow¬ 
ing extract:— 
I beg it to be understood as my decided opin¬ 
ion, that farmyard manure must always be the 
farmer’s main stay. Good farmyard manure 
will contain more or less of all the constitu¬ 
ents of our crops, but, in estimating its value, 
we must be contented to take into consideration 
only its more important constituents, and, in 
this way, I conceive we may obtain a suffi¬ 
ciently near estimate, by knowing the amount 
of nitrogen and phosphoric acid which it con¬ 
tains. 
In the management of farmyard manure, two 
different questions require to be considered. 
First, the production of a manure containing 
the greatest possible amount of nitrogen ; and, 
secondly, the successful conversion of that ni¬ 
trogen into ammonia. It is not unimportant, of 
course, that the other constituents of the ma¬ 
nure should be present in abundance, but it 
may be assumed, as generally true, that the 
treatment likely to produce the greatest amount 
of nitrogen, will be that which produces the 
most valuable manure in othe'r respects. In re¬ 
gard to the first of these questions, there is a 
want of definite information. It is a common 
statement, however, that the value of the ma¬ 
nure is dependent upon the nature of food with 
which the cattle that produce it are supplied. 
That, for instance, cattle fed upon oilcake pro¬ 
duce superior manure to those fed on turnips. 
I am aware that this opinion is not universal, 
as I have heard it disputed by farmers of skill 
and experience. I am inclined, however, to be¬ 
lieve that it is to a certain extent correct. Sup¬ 
posing, then, that two samples of such manure 
differ, it must be obvious that it is the dung and 
urine of cattle which differ; the litter mixed 
with such dung will be the same in both cases. 
As regards the general question of the pres¬ 
ervation of manure, I apprehend that the most 
important matter is its protection from air and 
moisture. In the way a common dung heap is 
made, we have, in fact, exactly the conditions 
to occasion loss of its valuable constituents. It 
is exposed to a more or less free current of air, 
which facilitates the volatilisation of the am¬ 
monia as it is formed; and it is exposed to the 
falling rain, which washes out the soluble salts, 
and what ammonia the winds have spared, into 
the subjacent soil. It is true that the former of 
these sources of loss can be got the better of by 
the use of acids or of gypsum, and mixing with 
dry earth ; but when the ammonia is thus fixed, 
as it is said, it is fixed only as regards volatility , 
for it is still soluble , and liable to be washed 
away by rain. 
In order to have farmyard dung in the best 
state, it must be preserved under cover; and, 
my impression is, that the introduction of cov¬ 
ered dung pits is likely to prove of great im¬ 
portance. We have another matter to attend to, 
