September 15, 1881. ] JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 249 
planting by the Toltecs (Nephites) antedate. 0 , perhaps, many 
centuries the rise of the Aztec empire. Some of these are nearly 
50 feet in circumference, and from 100 to 125 feet in height, with 
huge limbs extending all round to a great distance, and being 
always clad with dry, bronzed, and fresh green leaves, mingling 
with drooping silvery Mosses, form the most enchanting bowers 
imaginable. The arrangement of these trees is in groves and 
double rows, sometimes crossing at right angles and affording 
splendidly shaded narrow avenues. An exceedingly fine spring 
of pure water gushes from the rocks of the south side of the hill. 
Three hundred and seventy years ago the waters of this spring 
were conveyed by the Aztecs to the city through an aqueduct of 
masonry constructed for the purpose. A portion is now forced 
with a steam pump for use in the gardens of the palace above, 
while the remainder still flows to the capital.” 
WHAT PLANTS USE. 
(Continued from page 183.) 
Having made a few remarks on the gases used by plants, we 
will now turn our attention to the mineral matters which they 
require, and which are found in the soil only. 
When wood is thoroughly burnt there is always left behind an 
ash which will not burn. This ash is wholly mineral, and is as 
absolutely necessary to the plant’s growth as are light and 
air. The elements, which may be present in small quantity 
only, are as necessary as are those which are present in much 
greater quantity. For instance, potash is present in the ash of 
Asparagus to the extent of only six per cent, while soda bulks as 
largely as thirty-four. Still we cannot say that soda is of more 
importance to the Asparagus plant than potash, for it will no 
more thrive without a due proportion of the latter than it will 
without the former. At the same time, a soil rather poor in 
potash, but with eight times more soda, will afford sufficient of 
both of these compounds. In the case of the Potato the case is 
quite different. Potash is present in the ash of Potatoes to the 
extent of fifty per cent., while soda seldom amounts to one per 
cent. Even the tyro will understand that a soil may be very 
suitable for Potatoes and yet fail to grow Asparagus, and vice 
versa. He will also understand that in ordinary soils Potatoes 
will make a heavy demand on the potash, and the Asparagus on 
the soda. He would also conclude that potash salt must be good 
for Potatoes, and soda for Asparagus, and would probably end by 
sprinkling kainitonhis Potato plots and salt among his Asparagus. 
This is a common practice, and chemical science has shown how 
it is that salt is so appreciated by Asparagus. This much to 
enable the uninstructed reader to understand what follows. 
Many elements enter into plants by the roots and are necessary 
to plants. These elements are chiefly in the form of compounds. 
We have already mentioned potash. Now potash is not an 
element, it is “hydroxide of the metallic element potassium.” 
Again, soda is also a compound, and common salt a still more 
complicated one, in which the metallic element sodium and the 
gaseous one chlorine play important parts. We shall mention 
many others, but every one are compounds of elements. We will 
take each compound as they are generally placed in analytical 
tables. By the time we are done we hope our readers, who have 
hitherto given no attention to the subject, will understand the 
value of the tables which appear from time to time in the Journal 
and other publications. 
Potash .—This is present in the ash of Potatoes to the extent of 
from forty-five to over sixty per cent., according to the soil and 
the variety. Many other plants contain large quantities, while 
others contain very little. Speaking generally, it is a good plan 
to insert plants which require only a small amount of any given 
mineral compound which may have been demanded in large 
quantities by the previous one grown on the same soil. Rotation 
of crops on this basis is proper and profitable ; as generally carried 
out it means nothing and does not secure the end aimed at. 
Potatoes may find enough of potash in the soil on which they 
are planted, or in the manure which is added, to bring one crop or 
more to perfection, and yet exhaust the soil of potash to an extent 
that would make Potato-growing unprofitable on that particular 
position until potash had again collected in the soil, either by its 
free application, by chemical manure, or in the ordinary way, 
being left there by other crops which do not require it, and there¬ 
fore only take other matters from the freshly applied manure, 
leaving the potash. As a rule, plants which have a large per¬ 
centage of potash in their ash have little soda, and vice versa. It 
seems that the soda takes the place in one plant that potash does 
in another. Both are alkalies : both have many properties in 
common, yet the one cannot replace the other in the economy of 
any given plant except in rare cases. We have therefore potash 
plants and soda plants. Soda plants, as we have called them, 
affect the seaside. Plants which affect inland districts generally 
contain potash instead. This rule is, however, by no means 
absolute. Here is a list of commonly cultivated garden plants 
which contain potash in large proportion, and therefore demand 
it in the soil. Potatoes, 45 to 50 per cent. ; Potato tops, 23 ; 
Apples (fruit), 35 ; Artichoke (Jerusalem), 44^ ; Broccoli (leaves), 
22 ; (heart), 47 ; Beetroot, 39 ; Beet tops, 21 ; Beans (common), 
from 27 to 38 ; (kidney), 35 ; (runners), 49 ; Cherries, 51 ; Cab¬ 
bage, 34 ; Cauliflower, 34 ; Celery, potash 22, and chloride of 
potassium, 33 ; Cucumber, 47 ; Endive, 37$; Gooseberries, 38^; 
Plums, 59 ; Grapes, 70 ; Vines (Grape), 34 ; Lettuce, 46 ; Leeks, 
33 ; Onions, 39 ; Pears, 54 ; Pine Apple, 49 ; Peas, 36 ; Rhubarb 
stalk, 59^; Strawberries, 21 ; Turnips (Swede), 33. 
The foregoing list of plants and fruits contain soda in their ash 
in much less quantity—sometimes only mere traces—and seldom 
more than 8 per cent. The exceptions are when the potash is 
present in less quantities than 40 per cent. The more soda the 
less potash, and vice versa. For instance, Apple ash contains 
35 per cent, of potash and 26 of soda. Artichokes contain 44 of 
potash and only traces of soda. Kidney Beans 36 of potash, and 
18 of soda ; while Grapes, which have only 3 per cent, of soda in 
their ash, have as much as 70 of potash. 
The following plants contain more soda than potash. Aspa¬ 
ragus 34, and also 12 of common salt. Strawberries 27. (In 
Strawberries potash and soda are nearly equal: they contain 21 
of the former.) Spinach 34, and 8 of common salt; Poppy 33 ; 
Corncockle, 22. Occasionally lime takes the place of both potash 
and soda, but it is generally in the parts of fruit or vegetables or 
grain-producing plants which are not used for food that lime is 
thus largely present. The parts which are used generally contain 
most potash. Thus Apples contain 35 per cent, of potash in their 
ash and only 4 of lime. Apple wood contains 63 per cent, of lime 
in its ash and only 19 of potash. Potatoes contain, off and on, 
about 50 per cent, of potash in their ash and only one of lime. 
The haulm contains 23 per cent, of potash in its ash, and as 
much as 43 of carbonate of lime.— (Liebig). Peas contain 36 of 
potash and only 10 of lime, while the haulm contains only 4 per 
cent, of potash and 47 of lime. We might enumerate many more 
cases, but this would only take up space. It is a rule, however, 
which is very uniform. Nourishing matter in vegetables, fruits, or 
grains has always a large proportion of potash and phosphoric 
acid associated or bound up with it. Mere woody fibre, or useless 
(for food) tops of any kind, have a greater amount of lime and 
less potash. This rule holds so good that one may say that the 
nature of mineral food required bv any plant may be ascertained 
by the use for food or otherwise the plant is to animals. 
Phosphoric Acid .—This is one of the principal compounds 
which plants use, and which is largely present in the ash of all 
plants cultivated for food. We append a list of plants and fruits 
with the per-centage of phosphoric acid found in their ash. Apple, 
12 ; Asparagus, 18 ; Artichoke, 10 ; Broccoli, 24 ; Beans (common), 
35 ; (French), 26 ; Cabbage, 12 ; Celery, 11 ; Gooseberries, 14 ; 
Grapes, 20 ; Onion, 20; Pears, 14 : Peas, 31 ; Potatoes, 11 to 15 ; 
Rhubarb, 15 to 20 ; Radishes, 40; Strawberries, 84 ; Spinach, 7f. 
What we have called soda plants contain a less amount of phos¬ 
phoric acid than potash plants, and less animal nourishment. 
In addition to the above plants require sulphur (which is gene¬ 
rally present in the form of sulphuric acid in combination with 
some of the alkalies), magnesia, silica, and iron, which are present 
in very considerable quantities in most of our cultivated plants, 
but not to the extent of what have been called the more impor¬ 
tant compounds. Still they are necessary, and no soil can be 
fertile, or manure perfect without them. 
There are others which we have not even named. They are 
still less important: some of them are not considered necessary 
at all, but even when found in plant ash to be only accidentally 
present. To enumerate them all in a very elementary article like 
this would be out of place.—S ingle-handed. 
(To be continued.) 
CANWELL HALL, 
THE SEAT OF A. B. FOSTER, ESQ. 
This is situated near the Tamworth and Birmingham Road, 
midway between the former place and Sutton Coldfield. The 
Hall is approached by two carriage drives, one from the Lichfield 
and the other from the Tamworth Road, at each of which entrances 
commodious and elegant lodges hare been recently built. 
Entering by the Tamworth lodge we do not proceed far along 
the well-kept carriage drive, which is nearly a mile long, before 
the eye is arrested by the charm and variety of the scenery. 
Looking to the right the landscape is really beautiful. Hill and 
