130 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ February 18, 1886. 
then it must be useful, since all such plant food must be taken up in 
solution. 
That the carbonic acid, which is one of the main products of the decay 
of humus, does in some way favour vegetable growth is very neatly 
illustrated by an experiment performed many years ago by Stoeckhardt. 
Three deep glass vessels, two of which had holes pierced through the 
bottom, were filled with soil, and Peas were planted ; through the hole in 
the bottom of one of the vessels and up through the soil there was passed 
every day a certain quantity of air, and up through the soil of another of 
the vessels a mixture of air and carbonic acid ; the third vessel was left to 
it-elf, and the condition of things in it was about the same as in an 
ordinary soil with a very compact and impervious subsoil. The weight of 
dried crop produced in the third vessel without any circulation of air was 
about 90 grains, in the soil through which air was circulated 162 grains, 
and in the soil through which air and carbonic acid were circulated 190 
grains. In some way the carbonic acid along with the air helped the crop 
amazingly, more than doubling it. This was not necessarily because the 
plant fed on this carbonic acid directly to supply itself with that most 
important element, carbon. It has been proved over and over again that 
vegetation supplies itself with carbon, at least mostly, if not entirely, 
from the carbonic acid of the atmosphere. The fair presumption is that 
the carbonic acid passed through the soil brought more plant food into 
solution, and so the crop was more liberally provided with this means of 
growth. 
In support of this presumption we have the fact demonstrated also by 
Stoeckhardt, that the very soil which produced the largest crop, and 
therefore had yielded up the largest amount of dissolved plant food, still 
contained the largest amount of soluble plant food, ready for the next crop. 
The quantity of such soluble food was, in the soil of the closed cylinder 
without any circulation of air, 22 grains ; in the cylinder furnished only 
with air, 43 grains ; and in the soil to which both air and carbonic acid 
were supplied, 60 grains. 
You will have noticed that the second soil, receiving only air, also gave 
a notable increase both of crop, and of soluble plant food left for the next 
crop. On first thought this result would appear to conflict with the 
explanation given of the increased crop in the third soil, that it was due 
to the carbonic acid passed through that soil along with the air. But there 
is not necessarily disagreement here ; it is quite reasonable to suppose 
that the humus in this soil, together with the oxygen of the air that was 
circulated freely through it, produced the same effect and in the same way 
as was produced by the carbonic acid ready formed in the third soil. The 
formation of carbonic acid from the humus can take place only in the 
presence of oxygen, and the more liberal the supply of oxygen the larger 
will be the production of carbonic acid from a given quantity of humus. 
In this second soil we had, as in all the others, the ordinary quantity of 
humus; the supply of air, with its one-fifth part of oxygen, was liberal; 
carbonic acid must have been produced freely ; and it would have been 
strange if there had been no increase of crop. Such a result would have 
tended to disprove just what we are seeking to prove, that the humus does 
a good work for the farmer by the carbonic acid given off in the soil as it 
decays, or oxidises, which two terms mean much the same thing. 
Another experiment shows in a no less striking manner the part that 
humus may take in bringing plant food into solution: a sample of a sandy 
loam was compared with another portion of the same soil to which some 
humus had been added ; in the course of the summer months, while a crop 
was growing vigorously on these soils, the quantities of potash that became 
soluble in the two soils were as 366 parts in the soil poor in humus to 574 
parts in the other ; the quantities of plant substance produced in the two 
cases were 5040 and 9800 parts. 
(To be continued.) 
STRAWBERRY PLANTS IN WINTER. 
“ W. S.,” page 87, objects to my statement that the practice of 
plunging the pots in an upright position, either in leaves or ashes in 
damp situations and in wet winters, often leads to disastrous results by 
the plants being kept in a constantly wet and sodden state during the 
period of rest, when comparative dryness should be their conditionand 
he points out to me that “ there is no necessity for this being so, if the 
site selected for that purpose be higher than the ground surrounding it.” 
It is quite evident that “ W. S.” does not comprehend my meaning. What 
I wished to show was that the rainfall in wet winters in this climate, 
especially when the small amount of evaporation is taken into considera¬ 
tion, is much greater than is beneficial to Strawberry plants in pots 
prepared for early forcing. I freely admit that in elevated and breezy 
positions where the evaporation is great no serious evils may result, but 
the case is very different in low-lying damp localities, where the dryness 
of the air is not sufficient to keep the plants plunged in an upright posi¬ 
tion in a healthy condition. The usual practice in preparing Strawberry 
plants for forcing is not only to pot them in strong loam, but also to ram 
the soil down firmly. Under these conditions rain cannot freely pass 
through the soil, and. in changeable frosty weather the space, as I ex¬ 
plained before, between the surface of the soil and the rim of the pot 
frequently becomes a mass of ice and the plants suffer considerably. 
“ Such a condition caonot, I venture to say, be the be3t winter quarters 
for Strawberry plants in pots intended for early forcing.” They may be 
oovered lightly with dry fern, and so long as the fern continues dry and 
can be removed daily no serious injury may accrue, although the labour 
and inconvenience is great; but at times the covering cannot be removed 
for days or even weeks together, when serious injury must result. I have 
tried both methods not only for fourteen, but for nearly forty years, and 
I have no hesitation in saying that the plan of stacking them on their 
sides in ash heaps is the most safe, economical, and satisfactory. 
“ W. S.” expresses a wish to know “ upon what grounds I arrive at 
the strange conclusion that the condition of Strawberry plants in pots 
which are laid on their sides in ashes during the winter and early spring 
months, is more nearly like that to which they are naturally accustomed.” 
My reasons for forming this conclusion are simply these. I have found 
by experience that after excessively wet winters not only do Strawberry 
plants in pots plunged in an upright position suffer considerably, but 
those in the open garden do so likewise, unless the position be elevated 
and comparatively dry. If we look to the States of Virginia and Carolina, 
whence came the Strawberries from which our cultivated species are 
chiefly descended, and where they are said to flourish in their native 
luxuriance, the winter and spring seasons are not only more severe than 
ours, but the rainfall during those seasons is less, while the air is consi¬ 
derably drier. Although the rainfall during the growing season is greater 
than with us, yet the evaporation and consequent dryness in such an 
elevated region, which is said to range chiefly between 500 and 700 feet 
above the level of the sea, must be much greater than we experience in 
this humid climate. The other vegetable products of these States also 
show most plainly what the conditions of climate are there, and wherein 
they differ to those of this country. These are some of the reasons which 
induced me to write the paragraph to which “ W. S.” objects, and these 
are also my reasons for concluding that Strawberry plants arranged as I 
have advocated are placed in more natural conditions than when arranged 
as “ W. S.” prefers, and I venture to think they are “ quite in harmony 
with those conditions under which the plant flourishes naturally.” 
In conclusion, I cannot forbear asking “ W. S.” how he arrives at 
the somewhat strange conclusion “ that the Strawberry plant in gardens, 
during the resting period, receives direct from the clouds three times 
the amount of water at the roots that it does at any other time ? ” I fear 
his rainfall tables are somewhat inaccurate.—T. Challis. 
It has been finally arranged by the Council of the Royal Horti¬ 
cultural Society to hold a Provincial Show at Liverpool in 
the ensuing summer. Through the liberality of the Worshipful the 
Mayor and Corporation of Liverpool, the Botanic Garden, and so 
much of the Wavertree Park as may he necessary, have been placed 
at the service of the Royal Horticultural Society, and no better 
place could have been found. The Show will be opened on Tuesday 
the 29th June, and will be closed on the evening of Monday the 5th 
July. 
- An obvious misprint occurred in the report of the United Hor¬ 
ticultural Benefit and Provident Society on page 110, still it is 
advisable to correct it. Instead of the contribution of 2s. to the deposit 
fund annually it should be monthly ; the other contributions are correctly 
stated in the report. 
- “ J. R. S. C.” writes “ Some one asks about CATCHING MOTHS. 
I presume he means moths in general, not those of the clothes moth 
group. Some sweet compound is effectual—treacle better than sugar, 
duly diluted and flavoured with rum or aniseed, some say ; but all these 
are uncertain at particular times.” 
- In the report of Mr. J. Pavey’s paper on the Culture of 
Hardy Fruit Trees, read at the Lee, Blackheath, and Lewisham 
Horticultural Meeting on the 29th ult., it is stated that Mr. Pavey advised 
dissolving 8 lbs. of softsoap in 4 gallons of boiling water for the destruc¬ 
tion of American blight. This was a mistake ; it should be 2 lbs. of the 
softsoap to the quantity of water stated. 
- At the fortnightly meeting of the Huddersfield Paxton 
Society, the President, Mr. G. W. Rhodes, in the chair, Mr. C. Smedley 
gave an excellent paper on the Amaryllis. The essayist, a good cultivator 
of this class of plants, was listened to most attentively. An interesting 
discussion followed. Mr. Jarmain, Vice-President, described some splendid 
hybrids he saw at Messrs. Veitch Sc Sons’ last season. A hearty vote of 
thanks to the essayist and Chairman brought a very pleasant evening to a 
close. On February 27th Mr. F. Milan, a practical hot-water engineer 
will give a paper on “ Domestic Hot-water Supply.” 
- “M.” WRITES, “ A year or two ago the pretty bulbous plant 
Freesia refracta alba was comparatively scarce, but it is now 
