2 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
t July 5, 1883. 
shell sand and corals, are generally applied unburnt, as 
their mechanical condition admits of their easy pulverisation 
and distribution, but hard limestones are generally burnt. 
Marls often contain as much as 95° per cent, of clay or 
other admixture. Such are hardly worth digging and apply¬ 
ing, except to light soils, when the land gets a liming and is 
made heavier at one operation. This often benefits peaty 
land considerably. When applied to heavy land they often 
do mischief. Instead of opening, as liming is intended to 
do, they have quite an opposite effect, because of the clay 
they contain, and the lime given is too trifling to be of any 
consequence. Marl often contains, however, as much as 
90° per cent, of carbonate of lime (calcic-carbonate), and 
such are very different from those of the other extreme. 
Gardeners—strangers in a locality—had better ask neigh¬ 
bouring farmers what the traditional value of this or that 
marl is before incurring expense in its use. Tradition in 
these things forms a very good guide. 
Chalk is of a much more constant nature than marl, not 
often containing more than 20° per cent, of foreign matter, 
and seldom that. Oftener it does not amount to more than 
1 or 2 per cent. Chalk and marl owe their efficacy to the 
presence of carbonate of lime. One ton of carbonate of lime 
contains nearly 8| carbonic acid (dioxide), and, as near as 
may be, llj of lime, or, as it is expressed in chemical 
nomenclature, 
Carbonic, dioxide or anhydride (C O 2 ) 44 
Calcic oxide .. .. .. (Ca 0) 56 
100 
When limestones are placed in a kiln along with fuel and 
burnt, the carbonic dioxide is driven into the air, and only 
the calcic oxide—or calcined lime—remains behind. This 
has a great chemical affinity for water. When water is 
poured on lime shells, as the burnt lumps are termed, a 
violent action takes place—strong heat is evolved, and the 
calcic oxide becomes calcic hydroxide, which is not a mixture 
of water and lime, but a new compound made up of water 
and (quick) lime chemically combined. The new combination 
contains 76° per cent, of lime (nearly) and 24° of water. 
Were it only a mixture instead of a combination, the mass 
would be wet, but it remains quite as dry as before. When 
this compound is exposed to the air it combines with the 
carbonic dioxide ever present in the atmosphere, and in time 
assumes its original chemical condition by becoming calcic 
carbonate (carbonate of lime). This is perfectly insoluble 
in water, calcic hydroxide being soluble in 732 times its own 
weight of cold water. This solution is known as lime water. 
When a stream of carbonic acid is passed through this 
solution the lime is at once precipitated—it has become the 
insoluble carbonate. The easiest way is to pass one’s breath 
through it by means of a straw or pipe-stem. Chemists 
generally pass the gas derived from the calcic carbonate by 
simply pouring acetic acid on chalk or limestone. This 
drives off the carbonic dioxide, which is conveyed by a simple 
apparatus through the lime water. 
Newly slaked lime (calcic hydroxide) acts much more 
energetically when applied to land than either chalk, marl, 
or mild lime, as burnt lime is termed after having again 
assumed the form of the carbonate. But burnt lime after 
slaking becomes an exceedingly fine impalpable powder, and 
for this reason it is better than either chalk or marl, because 
of its being easier distributed even after it has taken its 
original chemical form. Chemically the same as when 
unburnt, it is mechanically very different, hence the reason 
for burning ; but in the state of quicklime it acts with much 
greater rapidity than mild lime. When first applied it at 
once combines with any free acid it may find. The acid thus 
neutralised is in a sense removed out of the way, and the 
oxygen of the air reaches ucdecayed organic matter, and 
causes its more, rapid decay and consequent liberation of the 
plant food it contains. Humic, carbonic, or nitric acids 
preserve organic matter from waste, and hence such organic 
matter in soils deficient in salifiable bases become plant food 
very slowly. But when lime, especially quicklime, is applied, 
these acids at once become calcic salts, and the work of food- 
preparation goes on rapidly. Not only so, but sour soils are 
at once sweetened, heavy soils lightened, warmed, and made 
earlier. It is even said to materially forward the brairding 
of seeds, but whether wholly by direct action on the seeds 
themselves, such as removing the carbonic dioxide, or by 
providing them with a freer, drier, sweeter, warmer medium 
is not clear ; probably in both ways. 
The action of marl, chalk, or mild lime is very similar, 
only slower. Mild lime does not act with the same energy 
in organic compounds as caustic lime; hence it is more 
suitable for soils poor in humus. Caustic lime, by acting 
rapidly on humus and other vegetable remains, may with 
great advantage be applied to old garden soil rich in black 
mould. Such contains much plant food in an unavailable 
condition. The application of lime liberates it, and enables 
the operator to do without manure of any other kind for a 
time, while at the same time the soil is improved otherwise ; 
but on very light soils, or on virgin loams in which humus is 
not abundantly present, quicklime should not be applied, or 
only sparingly, and along with plenty of ordinary manure, 
otherwise the humus will be dissipated, which is what should 
be guarded against, as the presence of a certain amount of 
humus is necessary for fertility. Heavy clays are much 
improved by quicklime. It curdles the clay and renders it 
free and open. On sour bog land it often works little short 
of miracles. On these and also on light sands and gravels 
a dressing will cause white Clover to appear, when sowing 
the seeds would not! This would indicate that on such 
soils it might prove beneficial to Peas and Beans. —Single- 
handed. 
(To be continued.) 
CUTTING DOWN CHRYSANTHEMUMS. 
The note you published on this subject on page 538 of last 
volume is an important one, and undoubtedly refers to a practice 
that is not in general adoption. So far as I am aware the 
system of cutting down Chrysanthemums in June or early 
July originated in the neighbourhood of Manchester, and no 
doubt the plants that were referred to so approvingly in your 
report of the Manchester Show last November had been grown 
on the system under notice. It is the best of all methods of 
producing dwarf untrained plants with grand blooms. 
If I am not mistaken some pains were taken for a time to 
prevent the practice being known. But the day of gardening 
secrets is past, and those who plume themselves on the exclusive 
possession of a method of culture do not now remain long “ alone 
in their glory. ” 
Having practised this method, in common with some others 
growers in the south as well as the north, I may perhaps 
usefully give my experience. 
This is a critical time to cultivators of the Chrysanthemum, 
especially where they are grown for exhibition purposes. Many 
varieties should be cut back without delay—indeed many have 
been cut down. Jardin des Plantes, Princess Teck, Hero of 
Stoke Newington. Novelty, John Salter, Eve, Nil Desperandum, 
Cherub, Princess of Wales, Mr. Brunlees, Lady Slade, Guernsey 
Nugget, Pink Perfection, Mabel Ward, and Angelina should be 
cut down at once; while within a few days the Beverleys, Queens, 
Alfred Salter, Mrs. Haliburton, Barbara, Prince of Wales, Lady 
Hardinge, Mrs. W. Shipman, the Venuses, Golden Eagle, Reful¬ 
gence, Mrs. Bunn, Isabella Bott, Mrs. Heale, Emily Dale, Mr. 
Gladstone, Mr. Corbay, White Globe, Prince Alfred, the Rundles 
trio, Aurea Multiflora, Lord Derby, Beethoven, Yesta, and all 
very early flowering kinds should not be stopped later than the 
end of the first week in July. 
The plants are cut back in some cases to within a foot of the 
pot, others even to within 6 inches of the surface. It will be 
seen by this that some judgment is required in the matteix The 
later-flowering varieties are cut down earlier, in order that they 
may break earlier and form their buds at the same time as the 
naturally earlier varieties which are cut down later. Another 
advantage gained by cutting down is that in many cases it will 
make quite 2 feet difference in the height of the plants, enabling 
the cultivator to make better use of them for furnishing or 
grouping. 
