710 
THE GARDENERS’ CHRONICLE. 
[Oct. 14, 
those principles of Horticulture on which the most perfect 
vegetable growth depends. 
The only natural mode of perpetuating the constitu- 
tional vigour of a species is by reproduction from seed ; 
and it is strictly in harmony with this law of Nature that 
the various modes of propagation and cultivation are to 
be viewed. Thence it follows, that in proportion as the 
means employed for the multiplication of plants are arti- 
ficial in their character, will be the premature exhaustion 
of the individual parts thus multiplied ; in other words, 
if, in the propagation of any plant by cuétinys, the 
latter be taken from a specimen which is already partially 
exhausted by excessive development of its parts, or by 
excess of bloom, the parts thus detached will partake of 
the impaired vigour of the parent. And upon the same 
principle, a plant which has been in the first instance 
derived from its parent stock as a layer, will possess less 
constitutional energy than others derived from the same 
source as cuttings, in consequence of the layer already 
approaching its final maturity more nearly than the latter. 
The conclusions to be derived from the foregoing 
remarks are, that the several organs of a seed, a cutting, 
and a /ayer, are each endowed with a principle of vital 
energy varying in power from a seed downwards. It may 
further be stated, that the vital functions of plants are 
diminished in force in proportion as the primary develop- 
ment of their parts is prematurely hardened or matured, 
whether that arises from excess or deficiency of the 
elements which sustain them, Much that is superior in 
cultivation is known to depend upon the skilful applica- 
tion of materials adapted to the variations of local 
influence and after-management. In support of a pro- 
gressive and accumulative system of cultivation, the 
following principles may be offered, apart from those 
minor evidences which every successful routine of practice 
supplies. 
ist. ‘‘For the maintenance of a plant in health, it is 
indispensable that the supply of fluid by the roots should 
be continued and uninterrupted*,’” 
2d. ‘* The smallest leaf at the extremity of a branch of 
a lofty tree must assist in setting in action the absorbing 
power of roots, at whatever distance from the other 
organs those roots act. If this reciprocal action is not 
maintained without interruption, and if anything occurs 
to check it during the period of vegetation, the plant will 
suffer in proportion to the amount of interruption.f” 
rom these statements, it appears that whatever tends 
to protract or suspend the reciprocal action of the organs 
of plants, will, in proportion, impair their vital energy ; 
and it is the fitness of the uccumulative system to secure 
a continued supply of those fiuids which are essentially 
necessary for mature growth in plants, that constitutes its 
superiority over other modes of cultivation. This advan- 
tage is obtained by transferring plants, in their young and 
excitable state, to large masses of soil, of a texture and 
quality adapted to their growth, and so mechanically 
arranged as to enable their tender organs progressively to 
assimilate their food without being liable to excess of 
moisture, or to be retarded in their after-growth. 
A strong argument against the fitness of the restrictive 
system of shifting of plants, to attain simultaneous and 
accumulative vigour, is found in the tendency of that 
system to reverse the laws of Nature in regard to the 
formation and disposition of roots. This is an evil inse- 
parable from the ordinary modes of cultivation. The 
natural function of roots being the absorption of food 
through the medium of their extremities or spongioles, it 
is plain that their capability of answering this important 
end will be in proportion to the facility afforded them of 
extending and ramifying in search of the elementary sub- 
stances required for their respective organs. In admitting 
this view of the subject, it will probably be found that the 
amount of food thus obtained will be commensurate with 
the diffusion of the roots over a given surface. 
These opinions are strengthened by their 
with the physiological fact, that ‘roots augment in 
diameter simultaneously with the stem, and under the 
influence of exactly the same causes}.”” From this law 
an important inference is to be drawn in favour of the 
present argument; namely, that as an inverted or hori- 
zontal position of the stems and branches is calculated to 
diminish vigour and dispose to precocious fertility, so 
similar effects will attend an inverted or circular direction 
of the roots, by limiting their expansive movement, and 
lessening their exposure to the indispensable influence of 
atmospheric agency. 
But it may be said that cultivators can avert such an 
unnatural position of the roots, by reshifting previous to 
those organs being too far advanced ; to which it will be 
sufficient to reply, that such a mode of transferring plants 
previously to their being tolerably established, would not 
only be opposite to successtul practice, but attended by a 
risk with which few practitioners would venture to incur. 
That plants of slow and rigid habit (and others propor- 
tionately) should be fairly established in their respective 
Stages of growth, previously to being further excited, is 
sufficiently well known j and to attempt an opposite course 
would not only endanger the flowers, but tend to frustrate 
the Principal objects of cultivation—From Pazton’s 
Magazine of Botan: 
id 
* 6 Lindley’s Pri les of Horticulture, 
«© Theory of Horticulture,” p. 50. 
# “ Lindley’s Theory of Vital Actions.” 
not to be depended on for such a purpose. I do not con- 
sider any of the descriptions of C. epithymum which I 
can refer to sufficiently detailed to enable me to judge 
from them. From what I recollect of this plant, it is 
much smaller, and has a general tinge of red, which our 
plant does not possess ; but these are doubtful characters. 
The essential characters of two species so closely allied, 
and unfurnished with leaves, must be taken from minute 
differences in the parts of the flower, and it is impossible 
to speak very decidedly how far these may be permanent 
without seeing the two together in a fresh state. I find 
one character in the flower of both this and C. europea, 
which appears to me to have been hitherto imperfectly 
noted ; and I shall take the liberty of directing the atten- 
tion of future observers to it. The flowers have been 
described as furnished with ‘ scales,”’ seated on the co- 
rolla, and opposite to the stamens. But instead of dis- 
tinct scales, I find a continuous corona adherent to the 
base of the corolla, ‘but perfectly free above throughout 
its entire circuit. This corona has scale-like laciniz, or 
teeth, seated before the stamens, and it is these which 
have been described as distinct scales, Perhaps a very 
rude and imperfect sketch may convey an idea of this 
corona as it occurs in the two species here alluded to. 
eh 
Opened flower and scales of Cuscuta Eur: 
s =) gel a 
Opened flower and scales of Cuscuta trifolii, 
I observe, also, on opening and extending the corolla on 
a flat surface, that the corona ruptures readily at the base 
of each lacinia, creating a suspicion (for I can urge no 
more) that it may possibly be formed by the cohesion of 
subordinate parts (abortive stamens ?), which thus alter- 
nate with the stamens, instead of being opposite to them. 
These parts are very small, and their relation may be 
easily overlooked ; as we see by the figure and description 
of C. europa in English Botany, where that species is 
represented as having no scales at all.—J. S. Henslow, 
Hitcham, Suffolk, Sept. 13, 1843. 
AMMONIA. 
Tux observations of Mr. Lawes on the value of Am- 
monia as manure, in last week’s Chronicle, are very inter- 
esting, and in several respects I entertain the same opinions; 
some of his statements, however, appear more question- 
able, so that without further evidence I think we should 
hardly be justified in adopting his conclusions, and giving 
up the old theories which have hitherto been received. 
Mr. Lawes considers that it is more important to supply 
plants with Phosphates than with nitrogen, and in this 
I cordially agree with him, but when he seems to think 
Ammonia of little or no value as manure except indirectly, 
I feel hardly prepared to follow him. It is pretty gene- 
rally considered that’ plants must derive the nitrogen 
which they contain, either from Ammonia or some other 
compound containing it, and that they cannot assimilate 
it direct from the air; if this be the case, it is evident 
that they cannot form azotised matters unless they are 
supplied with Ammonia, or some other compound con- 
taining nitrogen, either from the air or from the soil. 
Now the quantity of nitrogen which can be supplied in 
this way to plants is by no means large ; if therefore the 
supply of it can ‘be increased in moderation, the means 
of forming azotised matters, and consequently one of the 
means of luxuriant growth, will be supplied to plants. On 
examination, it appears, that the great majority of the 
operations of culture, amongst other things, facilitate the 
absorption and retention of Ammonia and the compounds 
of nitrogen. 
In studying the action of inorganic manures, it is neces- 
sary to consider their action in several points of view: 
their chemical effects must be distinguished from those 
which are merely mechanical, and the chemical nature of 
the soil must be known, that the chemical effects of the 
manure may be ascertained. In adding, for example, to 
certain soils lime or other bases, we give to the soil the 
power of assisting in the transformation of Ammonia into 
nitric acid. We may merely add potash ; but by so doing 
we give to the soil the power of fixing a quantity of nitro- 
gen, as nitric acid, and thus enrich the soil by indirect 
means. The nature of the soil is of very great importance 
in examining the action of saline manures: we apply 
various salts of Ammonia, and carefully measure the pro- 
duce obtained by the use of each; but we forget that the 
salts may be decomposed before they reach the roots of 
the growing plants, and that, by the ordinary processes of 
double decomposition, the salts we apply may be com- 
pletely changed in the soil. 
On soils rich in azotised matters, containing Ammonia 
or salts of nitric acid in considerable quantity, it would 
not be reasonable to expect benefit from the use of 
ammoniacal manures ; butin soils not of this description 
I believe they will always be found of value; how mucl 
of the benefit derived from them is due to the acid they | getation, is proved by the luxuriant manner in W 
the Ammonia itself is of great value. If the sulphuric 
acid of sulphate of Ammonia is the most important ingre- 
dient of that salt, then sulphate of Ammonia would produce 
but little effect on soils containing much sulphuric acid ; 
whilst the contrary, I believe, is the fact. The compara- 
tive effect produced by different salts of Ammonia varies 
much, and appears to depend principally on the nature of 
the soil. I have recently seen the muriate producing 
larger crops than either the sulphate or the phosphate, 
when applied to Wheat and Potatoes. Whilst speaking 
of the effects produced by Ammonia, I may mention a 
curious fact which T lately observed, and which bears upon 
the subject. I found that plants of Tobacco manured 
with salts of Ammonia contained, in proportion, a far 
larger quantity of potash than similar plants grown in the 
same soil, but not manured with Ammonia. It is, I 
think, evident, that the salts of Ammonia increased the 
vigour of the plants, and enabled them to absorb from the 
soil, a larger quantity of potash than they could otherwise 
have done. The effects of guano are certainly not wholly 
due to the Ammonia which it contains; a great part is 
no doubt due to the presence of phosphates, but | have 
generally found that the best guano was that which was 
richest in Ammonia. 
Mr. Lawes asks, ‘‘ What proof have we that plants are 
unable to supply themselves with Ammonia from sources 
unknown to us ?—and how far may the increase of crops 
by the addition of substances containing Ammonia be at- 
tributed to that element?” To prove that we know all 
the sources of nitrogen is of course impossible ; we know 
that plants may obtain it, both from the soil and from the 
air, but they may obtain it in a manner that we are still 
unacquainted with, though it certainly appears more than 
probable that they can and do obtain it from Ammonia 
and nitric acid—sources which are quite sufficient to 
account for the quantity they commonly contain, The 
fact that rotten dung is far superior to fresh dung, does 
not appear to me to prove that the Ammonia lost during 
its putrefaction was useless, but rather that the nitrogen in 
the rotten dung is in a state which plants can assimilate, 
whilst that in fresh dung is less capable of being absorbed 
by them.* I do not for a moment suppose that plants 
would grow if deprived of earthy phosphates and bases, 
but supplied with Ammonia, any more than that they 
would flourish without light; but I believe that a source 
of nitrogen is as essential to plants as a supply of phos- 
phates. The best of all manures are those which supply 
both phosphates and Ammonia. Farm-yard manure is of 
this description. It is a question well worthy of consi- 
deration, whether plants do not derive a very notable 
quantity of earthy matter from the air. I need not men- 
tion the great distance to which sea-salt is carried by the 
wind, but I cannot help suspecting that a greater quantity 
of solid matter is carried about in the air than is commonly 
supposed. 
I hope these hurried remarks will elicit further ob- 
servations from those who have practical, experience in 
the action of manures.—Z. Solly. 
AMATEUR’S GARDEN.—No. XLI. 
Were I desired to point out what I consider the 
greatest, defects in garden scenery, I should have very little 
hesitation in enumerating deep and irregular raw-edgings 
to the walks, as the first defect; walks and borders 
deficient in gravel or soil, as the second ; and tall, clumsy 
box-edgings, as the third. In my estimation, deep an 
irregular edgings are a most intolerable deformity, and 
yet, to such an extent does this deformity prevail, that of 
all the gardens I ever visited, I could not name half-a- 
dozen that are free from it. At this place, though the 
walks have been all made within the last five years, the 
edgings are so irregular, that in one place they are from 
three to four inches deep, while, perhaps within a few 
yards in the same walk, the grass is below the level of the 
gravel. Ido not attribute any fault, in this respect, t0 
my predecessor, because the irregularity is not greater 
than may be noticed in most other gardens, but I merely 
point it out as an instance of bad taste, in an otherwis® 
highly kept garden. Now, the first operation in the way 
of improyement which I shall undertake this autumn, will 
be to have all these edgings properly levelled, and in doing 
this I shall have all the grass taken up two feet wide from 
the walk on both sides, and then make them perfectly 
level, allowing for the grass, when laid down again, to e 
not more than one inch above the level of the gravel. I 
shall then have this grass rolled once a week through the 
winter by a heavy roller, so that in the spring, ee 
dress the edgings off before trimming the walks, they W™" 
not be more than half an inch in height,—and after UDA 
have been once properly formed and cut, I shall never, 
I can possibly avoid it, allow them to show a raw © ie 
again,—at least, not more so than is necessary to keep t 
lines and curvatures of the walks as true and regular 4S 
possible, 
Foreigners, when viewing the gardens of this gna) 
are always pleased with the beauty of our close-cut pais 
and gravel-walks, and I believe it is not assuming 
much to say, they are the finest in the world. ea 
however, as this fact is to British vanity, I believe ‘a Ae 
been a prolific source of carelessness, in leading us to 
ris f 
satisfied with what our walks and Beers Ee 
making them what they ought to be. heen yet the 
ig increase ve- 
hich plants in 
—* That the vapours given out by fermenting dun: 
contain is a separate question, but I am convinced that | the vicinity of dunghills grow. 
