226 JOURNAL OF HORTICULTURE AND COTTAGE GARDENER . t septemter 7 , m 2 
more to answer for than arises from their low estimate of earth- 
closet manure. By constantly neglecting to assign any value to 
potash in manures (it is usually lumped in with soda, as “ alkaline 
salts, magnesia, &c.”), and by disallowing all money worth for 
magnesia, they are delaying the progress of scientific agriculture 
as much, perhaps, as they have done by their eccentric valuations 
of different forms of phosphoric acid. A friend remarked to me 
a few days since when discussing this subject, “ Chemists have 
been far too much accustomed as a body to exalt the merits of 
nitrogen and to depreciate the effects of potash, magnesia, and 
other fertilisers. They have apparently been caught by the rapid 
show which nitrogen produces, but which is after all a mere flash 
in the pan, accompanied, unfortunately for the future prospects 
of the country, by a most impoverishing effect upon the soil. The 
fact is, the whole question of the valuation of manures requires 
revision.” But on this occasion I wish to confine my remarks to 
magnesia only, to which I now return. 
Ville, in his admirable treatise on “Artificial Manures,” does 
not, I venture to think, write on this subject with his usual judg¬ 
ment. He found, as your review above mentioned indicates to 
have been, to some extent at least, the experience in Sussex, that 
the omission of magnesia from the soil and manures used produced 
disastrous effects. Ville quotes from Davy the analysis of six 
soils, in one only of which magnesia does appear to have been 
present; and he also quotes an analysis by M. Rivot in which 
only traces of magnesia occur ; and yet he tells us that he excludes 
magnesia from his manures, as also some other ingredients, 
“because the soil is provided with them naturally.” But this is 
true likewise of ingredients which he thinks it most essential to 
add. The real question is, Do these ingredients occur in the soil 
insufficient abundance? “Every field,” says Liebig (page 213, 
“ Laws of Husbandry ”), “ contains a maximum of one or several, 
and a minimum of one or several, nutritive substances. It is by 
the minimum that the crops are governed, be it lime, potash, 
nitrogen, phosphoric acid, magnesia, or any other mineral con¬ 
stituent : it regulates and determines the amount or continuance 
of the crop.” And again (page 72) he says, “ To be productive 
in the fullest sense of the term, a soil must be able to afford food 
at all points in contact with the roots of plants ; and however 
small this quantity of food may be, it must necessarily be distri¬ 
buted through every part of the soil.” Now it is a noteworthy 
fact that very generally (with the exception apparently of the 
soils analysed by Sir H. Davy at a time when analytical methods 
were comparatively imperfect and the magnesia may have been 
overlooked) “ barren ” soils are deficient in magnesia, whilst 
“ exceptionally fertile ” soils contain it in abundance. (See ana¬ 
lyses given at pages 519-527, Johnson’s “ Lectures on Agricultural 
Chemistry and Geology.” The evidence is the stronger, perhaps, 
since Johnson’s attention does not appear to have been attracted 
by this point.) 
Liebig, again, in his “Natural Laws of Husbandry,” (pp. 257, 
258), shows that the seed ashes of plants such as Wheat, Peas, 
Beans, and Rape contain larger proportions of magnesia as well 
as of potash than is found in guano—that most valuable of all 
manures. And he urges upon his readers the importance of the 
part which magnesia appears to take, not only in the formation 
of seeds, but also (in common with lime) by influencing perhaps 
“ the presence of the soluble nitrogenous compounds (albumen 
and casein), or of the insoluble (gluten or vegetable fibrine).” 
It appears from the experiments which were made in different 
localities in 1842 on cereals, Turnips, Potatoes, and Clover at the 
instance of Professor Johnson, that these views of Liebig were 
supported at least by practical results, as the use of sulphate of 
magnesia proved to be very advantageous in all cases. And we 
know that Messrs. Lawes and Gilbert, in their Rothampstead experi¬ 
ments, always made this salt a constituent of their “ mineral 
manures,” a practice followed also by Yoelcker in the trials at 
Woburn. Why, then, I may fairly inquire (in the name of all the 
fertilisers) does not magnesia carry some value with chemists in 
estimating for buyers the worth of a manure ? I leave it to the 
agricultural chemists to explain this; but I am glad to see that 
M. de Joulie in a paper on “ Permanent and Temporary Meadows 
and Pastures,” which was awarded a gold medal by the Socffitd 
des Agriculteurs de France, and of which a translation appears in 
No. xxxv., part 1, vol. xviii., the last number published, assigns 
to magnesia a value of 3'048d. per lt>. (or about 5s. 8 d. a unit) 
which is nearly half as much as he assigns to potash, and almost 
three-fourths of the price he quotes for phosphoric acid. Have 
any of your contributors any definite information tending to 
confirm or contradict the correctness of Monsieur de Joulie’s 
estimation ? 
Since writing the above I have observed in the last issue of 
the Gardeners' Magazine (August 26th, p. 453), a notice of a paper 
by Mr. H. Scott of Alnwick on the “ Valuation of Manures.” 
This was read before the Coquetdale and Vale of Ain Agricultural 
Association, and it puts the value of magnesia at something like 
the same value as Monsieur de Joulie. May these indications of 
a growing appreciation of this too much neglected fertiliser pro¬ 
duce some change in the valuations of our agricultural chemists, 
and render these valuations more worthy of the farmer’s confi¬ 
dence as correct indications for his guidance.— Inquirer. 
HARDY PLANTS IN FLOWER IN AUGUST. 
These are very numerous, but the following are very striking 
and showy :—Scabiosa graminifolia, a very pretty dwarf species 
of close growth with narrow glaucous leaves. The flower stalk rises 
to about 9 inches or a foot high, with capitula about 1^ inch 
across of a lavender-blue colour, and they last some time in 
beauty, and being very floriferous it is really a good plant, the 
foliage at all times being pretty. It delights in a dry position 
and sunny, the rockery being a good place for it, and in such a 
position it is perfectly hardy. I have found it very slow to strike ; 
or it can be easily secured at most dealers, but it is easily raised 
from seed, which ripens outside. There is also another Scabious 
named S. suaveolens, and it is quite distinct from the last. It has 
pinnatifid leaves, and it grows from a foot to 18 inches high, pro¬ 
bably more in rich damp soil; but I plant it on the rockery or in 
a dry position with poor soil, and it makes a pretty dwarf plant 
crowded with flowers. The flower heads are about the same size 
as those of the last, of a pinkish-purple colour and sweetly scented. 
It is easily obtained by divisions, cuttings, or from seed ; but it is 
certainly a plant not frequently met with, although far superior 
to many more generally cultivated. S. caucasica is a much better 
known plant, and even more showy than either of those mentioned 
above. It has a tufted habit, while the flower heads are of a rich 
lavender or sky-blue colour, on peduncles about 18 to 24 inches 
high, or even more in strong soil, and when the plant is in good 
condition it is extremely showy—in fact, one of the best border 
plants now in flower, most serviceable for cutting purposes, the 
colour being extremely delicate. 
What a very variable genus is Phyteuma, usually with curious 
heads of horned flowers ! but what a strange species is P. stylosa- 
stricta ! Many enthusiasts have expressed astonishment at the 
plant. Mr. Leo Grindon wondered at first what Campanula it 
was ! No, it is not a Campanula, for there are not five stigmatic 
divisions. It is a Phyteuma with erect spikes, sometimes 
branched, about 18 inches high, of blue flowers about half an inch 
across, and quite open. Is it very common ? I have only met 
with it at Messrs. James Dickson & Sons’ of Chester, where there 
are many curious hardy plants in flower on the rockery. Phy¬ 
teuma Scheuchzeri is one of the apparently endless kinds with 
spherical heads of bluish-purple flowers ; but it is a very pretty 
one, with slender stems from 9 to 12 inches high very freely pro¬ 
duced. There are a number of species and varieties, many of 
which are not found in our gardens at all, although natives of 
southern Europe. Some of them certainly are difficult plants 
to cultivate, but if care is bestowed upon them they can be 
established. 
A plant known in many collections as Chrysanthemum maxi¬ 
mum is very showy, with a bushy habit, 3 or 4 feet high, thickly 
covered with flower heads like very large Ox-eye Daisies, but a 
much stouter flower for cutting purposes and border decoration. 
It is really a fine plant, most easily grown and readily increased 
by cuttings, which root freely in a young state. 
Amongst yellow-flowered Composites the two most showy are 
Harpalium rigidum and Coreopsis lanceolata, or grandiflora as it 
is frequently called. The former (see fig. 39) is a very showy 
plant, exceedingly floriferous, and of a freely branching habit. 
The leaves are more or less bluntly lance-shaped and rough ; the 
capitula are from 3 to 5 inches across, with broad deep yellow 
rays and yellow disk florets. It grows from 2 to 4 feet high, the 
lesser height being obtained when planted in a dry position. It 
rapidly increases itself by underground stolons, which can be 
separated in the autumn and planted where required, as it is per¬ 
fectly hardy. In the north it is now in fine character, but in the 
south it is much earlier in bloom—at least a month. The Coreop¬ 
sis grows about the same height, forming a large bush crowded 
with flowers, which measure from 2 to 3 inches across, with fewer 
and broader rays than the Harpalium and thinner in texture, and 
the disk is smaller. The leaves are more fleshy. As a plant for 
supplying an abundance of yellow flowers for cutting it cannot be 
surpassed at this season ; the flowers have a very light appear¬ 
ance, and are most useful for vases, and the plant is equally useful 
for the border. 
Erodium carnifolium is a very pretty species of Heron’s-bill. It 
