AE 
THE GARDENERS’ 
CHRONICLE. 
(Dec. 23, 
are introduced into the gutters, and after travelling all round 
the house under the gutters it passes under the back path and 
escapes by a chimney-place behind the back wall near the boiler. 
Both for economy and utility this plan of heating promises to 
be all that could be desired. Moisture can either be obtained 
a simple contrivance 
supplying it with water. house is a semicircle with 
eight sides, and has the principal entrance in front. The abov' 
arrangement has been in operation for some time, and I find it to 
answer the purpose very well. Many gardeners have also seen 
it, and all bear testimony to the excellence of the plan.— 
C, Ewing. 
° 
Iebielos. 
Experimental Researches, Chemical and Agricultural, 
showing Carbon to be a Compound Body, made by 
By Robert Rigg, F.R.S. Smith and 
A Book with this startling title has recently been pub- 
lished, purporting to be the result of many years’ study 
and careful experiment, and containing statements which 
if borne out by satisfactory evidence would effect a com- 
plete revolution in Chemistry generally, more especially 
in that branch of it which relates to organic matter. 
the old theories which he discards. Mr. Rigg’s experi- 
ments are very numerous, and appear to have been care- 
fully performed; but in several instances they want that 
rigid exactness and minute attention which is essential 
to experiments of this delicate nature. For example, 
when he causes plants to, grow in water, in confined por- 
tions of air under bell-glasses, the edges of which dip into 
water, it is open to question whether carbonic acid ma: 
a pass, through the medium of the water, into the bell- 
glass. : 
Mr. Rigg observes, that it appears doubtful whether 
plants can derive their carbon from the air, and thence 
seems to pass to the conclusion that therefore they must 
make it. To establish this point, he relates numerous 
experiments to prove that plants growing in circumstances 
where they cannot obtain carbon from any known source, 
still grow and are subsequently found to have acquired 
carbon. As has already been said, he does not satisfy us 
that all necessary precautions were taken to keep out 
carbonic acid ; and secondly, if, as he supposes, the plants 
in his experiments had made so many grains of carbon, 
the question arises, out of what did they make it! They 
could not create matter, and therefore must have formed 
the carbon out of some matter already existing. He should 
have proved the disappearance of some substance, as well 
as the appearance of the carbon. We are believers in the 
decomposition of carbonic acid by plants, and are there- 
fore predi d not to adopt Mr. Rigg’s theory ; but at 
The Author commences by a series 
respecting the amount of carbon in the soil, and shows 
that the quantity removed from it in the form of crops, 
amounts in a few years to much more than the soil itself 
originally contained, or has received in the form of 
manure. The principal conclusion which he draws from 
this calculation is doubtless true, viz., that plants cannot 
derive the whole of their carbon from the soil; but the 
calculation itself is erroneous, and based on false princi- 
ples. It is useless to make calculations respecting the 
composition of a field, in the manner that a chemist 
speaks of the contents of a bottle, or crucible. In the 
latter case a known weight of certain substances is heated, 
or mixed, or acted on in some way, and a definite result 
is obtained; but in the case of a field there are many 
circumstances that cannot possibly be taken into account. 
It is true we know what the farmer adds in the shape of 
manure, and what he removes in the form of crops of 
various kinds, but this will not enable us to form con- 
clusions, or to make accurate calculations respecting the 
changes which have taken place in the composition of 
the soil. 
Mr. Rigg gives several tables, showing the quantity of 
carbon existing in a given soil, that added in the form of 
manure, and the amount abstracted by the crops, and 
then proceeds to strike a balance; but he omits all 
mention of the roots of the crops each year left in the 
soil, to add to the store of organic matter which it con- 
than two tons of dry organic matter per acre. 
impossible, in the existing state of knowledge, to form 
accurate calculations of this kind, and if they are not 
accurate they are worse than useless. Our Author next 
inquires into the other sources of carbon, particu- 
larly the atmosphere, endeavouring to show by the 
experiments of others as well as his own, that the car- 
bonic acid of the air is not the chief source of the carbon 
of plants. In the outset, he states that plants impart 
carbonic acid to the air; but the experiments by which 
he endeavours to prove this are by no means satisfactory ; 
at the same time he appears to admit that they have the 
ower of decomposing that gas, although he thinks it 
questionable whether they abstract more of it than they 
impart to the air. The statement that plants evolve car- 
bonic acid is in direct opposition to the careful experi- 
ments of Mr. Pepys, who never found it given off by 
healthy plants. 
Mr. Rigg next proceeds to examine De Saussure’s ex- 
periments on the quantity of carbonic acid in the air, 
and conceives the discovery by that observer that more 
carbonic acid exists in the air during summer than 
in winter, to be opposed to the theory that plants 
decompose it. But these experiments do not in 
reality prove anything, and cannot be used as argu- 
ments against the decomposition of carbonic acid, 
because we do not know what other circumstances in- 
fluence the absorption or decomposition of that gas at 
other times. There are other experiments which show 
that the quantity of carbonic acid is greater in the night 
than in the day; these prove that some agent is at work 
during the day to effect its decomposition, which does not 
operate during the night; whilst the fact that there is 
more of it in the summer than in the winter, is no proof 
that plants do not remove it. During spring and sum- 
mer, when plants are growing, it may be necessary that 
there should be a greater supply of carbonic acid to the 
air than dur the autumn, when they have ceased to 
“requireit; andyon the other hand, at the latter period, 
various’ meteoro ogical causes come into play, which 
may tend to diminish the carbonic acid of the air 
thé uniformity of its composition. But 
this, in fact, is:.mere speculation, and however inju- 
rious or plausible such theories may appear, they throw 
little light on the questions immediately before us. Mr. 
Rigg is, ag a chemist ought to be, sceptical and cautious 
in believing ‘he theories of others, which, he says, are not 
based on facts, or are not supported by sufficient evidence ; 
“but here his caution ceases, for having thrown aside the 
theories of others, 1,.¢ advances a new one of his own, and, 
#8 it appears to us, ne far less supported by facts than 
‘0. 
P Pp 
the same time that we object to his conclusions and doubt 
his results, we do not altogether deny them. 
The opinions of a zealous experimenter are always 
entitled to respect; and though they may not carry con- 
viction, or may even prove to be erroneous, should be 
treated with courtesy, and not be ridiculed in the contempt- 
uous manner applied by a great German chemist lately 
towards a Scotch observer. Such criticisms are unworthy 
of men of science. We do not pretend to pass judgment 
on Dr, Brown’s experiments, which are purely chemical, 
but we regret to see a philosopher like Liebig forgetting 
the dignity of science, and descending to the littleness 
of personal abuse. 
We cannot follow Mr. Rigg through his long series of 
experiments, which would oblige us to write a commentary 
on his book, and enter into many chemical inquiries. 
After carefully reading it through, the impression it leaves 
is, that he does not establish the theory he has pro- 
pounded; his experiments are not varied enough, and 
frequently stop short there where further information 
would be most desirable. At the same time, it is impos- 
sible to read his book through, without coming to the 
conclusion that he is one of the most laborious and indus- 
trious ;chemists in the’ country.j For our own parts, 
we are disposed to give his experiments the best consi- 
deration ; for it is never to be forgotten that some years 
since, when Mr. Rigg announced the fact that nitrogen 
was always present in all parts of plants, his experiments 
were questioned and disbelieved ; nevertheless, the truth 
of his statement is now generally admitted, whilst the 
credit of the discovery is most unfairly given to others. 
Table of the Elementary Constituents of Crops. 
By James Haywood. eet. Simpkin and Co. 
Tus is one of those useful Tables which condense a 
volume into a page. It shows of what chemical constit- 
uents the more important crops consist, how much 
nitrogen and fixed ingredients are extracted from land by an 
average crop, according to the evidence of Boussingault 
and Sprengel. On the other hand, it gives the con- 
stituents per ton of all the more valuable manures; so 
that by comparing the one with the other, it may be seen 
how to restore to a field the materials of which a crop 
has robbed it. This Table should hang in every farmer’s 
room. 
On the Respiration of the Leaves of Plants. By W. H. 
Pepys, Esq., F.R.S. From the Philosophical Transac- 
tions. 1843, Part IT. 
Ir is a universal opinion among Vegetable Physiologists 
that plants not only decompose carbonic acid, but exhale 
it. Sanssure found that carbonic acid is parted with 
when plants remain in obscurity ; Burnett observed it to 
be a constant phenomenon ; and Liebig roundly asserts 
that it must be given off with the water of perspiration in 
which it is dissolved. It certainly does appear to us that 
when certain plants, such as the Orange Lily, in a state of 
health, are plunged in lime-water, carbonate of lime is 
slowly formed on their surface, which can only be owin 
to the extrication of carbonic acid. All these supposed 
facts are, however, found in direct opposition to some 
very carefulfexperiments by Mr. Hasledine Pepys on the 
Vine and the Fig, from which it appears that, in those 
instances at least, no carbonic acid whatever is parted 
with, but that the whole respiratory action of plants is 
confined to decomposing carbonic acid and liberating 
oxygen. In no one instance was he able to detect a single 
trace of carbonic acid in the air surrounding the leaves 
on which he experimented, although the apparatus was so 
contrived as to show the existence of a very minute 
quantity, if it had been present. This is a most unexpected 
result, to which we trust that experimental Physiologists 
will direct their attention. : 
CALENDAR OF OPERATIONS for the ensuing week. 
Havine repeatedly invited criticism on things mentioned in 
the Calendar, 1 beg to admit in detail a few remarks that have 
reached me, as I find I could not well condense and divide them 
under the different heads with other private correspondence; 
and now that I am within one week of the end of my series, 
again repeat that I shall feel obliged to parties who will send 
any remarks or fair criticism on what I have advanced in this 
Calendar ; and it’ I use these remarks in the Chronicle I shall not 
mention pames woless it is wished, ‘I see,’’ says @ corre- 
spondent, “that you advocate planting out Pines over tanks 
I have some so planted, end the: i 
there will be some difficulty in starting them without starting, 
all at the same time; secondly, there will be no means of 
retarding them when in the last stage of swelling without 
retarding the whole in one pit; and thirdly, we shall be obliged 
to cut the fruit when they 
event of having too many frui 
things against the facility of by 1 
system, I am disposed to take my plants up in February, and 
subject them to the one-shift system. This, with the advantages 
of planting out, offers the preference of managing the fruit as 
circumstayces may render it necessary. As for command of tem= 
perature and moisture, the tank-system offers every advantage.” 
Here it will be seen that the ‘‘ advantages of planting out’? are 
advocated for the plants at an early stage(?) and the conve- 
ripe at once. Weighing ga 
wn: I clear 
Again, i 
boiler, &c., you will probably feel disposed to change your 
opinion as to the necessity of having a flue, in order to take 
the waste heat.” Although I have pulled down all flues here for 
the last 15 years, to make way for iron pipes, I am not unfriendly 
to flues. Mr. Paxton grows better crops of fruit with flues only 
than many gardeners can grow with hot-water pipes. I only 
recommend them in connexion with gutters and tanks, except 
for detache Thave L 
attempts to get carly Grapes in the way I lately suggested ; but 
as the first crop, in 1841, “‘ was the offspring of accident,” pro- 
bably the economy of the Vines might be deranged for some 
ometimes useful conclusions may be drawn from the 
result of accident, but they are dangerous guides at best. Ihave 
ocieties and the Gardeners’ 
not make use of them here. f 
Institution early in 1839, for defrauding the funds, and there is 
not the least chance of his getting a footing there again. ‘The 
funds of this institution are as safe as those of the Bank of 
England, and are ini by high] Pp officers: 
Every gardener who can afford to do so should join this institu- 
tion. The members and their friends meet, dine, and transac’ 
business as usual on the 11th January, but thereis not a farthing 
of the funds of the Society spent at these useful meetings. 
I,—KITCHEN-GARDEN AND ORCHARD; 
In-door Department. 
PineRY.—A good Pine-grower, who favoured me with some 
letters last autumn, will now see there is plenty of room for 
treating them in the French manner, &c, I cannot say whethet 
Mr. Knight grew his young plants in dung frames; he often told 
me he preferred leaving the strongest sucker on the old plant, 
end he potted this old stool with the sucker, and sometimes will 
two suckers attached, in deep, upright pots, and earthed them 
up from time to time, as the roots advanced ; this plan did 
not, I think, originate with Mr. Knight; it was published in the 
i i ‘ociety”? in 1818 or 18195 
however, it is an economical mode of growing Pines which yor 
‘ou wi 
Be 
INERY.—This mild season has been more unfavourable to the 
very late-kept Grapes than when we experience some shar? 
frosts, as, in a general way, with frosts we have more sun it 
winter and a‘drier If the bord tside of the early 
Vinery are well covered, and the stems, also, if outside, with, 
moist atmosphere inside of from 50° to 60°, and the plants in 
good condition, I see nothing more to be wished. If every plant 
was as easy to manage as the Vine, gardening would, indeed, be 
a simple process, 
eACH-HOUSH.—The Peach, on the other hand, is like # 
spoiled child; the least thing will put it out of its way ; and Y° 
must not only watch it narrowly, but anticipate its wan's 
Currents of cold air admitted in front is injurious to these trees 
when they are forced very earl: d 
CucumBers.—Few persons who grow winter Cucumbers nee 
assistance from Calendars, but I find many wish to learn no} 
this branch is going on in this neighbourhood. It would be very 
difficult for me, however, to convey an idea of the enthusiast? 
@ makes a see 
his mode of growing them. As far as I can learn, all B 
growers employ strong heat, and like Mr. Mills, allow large 
portions of air; but for about three weeks before the day. 
competition some growers keep their plants ‘very hot, and Lan 
little air,” and no more moisture in the atmosphere than W 
“keep the blossoms from shrivelling. 
Out-door Department. e 
In the first Number of the Chronicle, (page 6,) willbe seen ee 
Mr. Pontey, of Plymouth, manage renew Vines which g!© 
“Dadly upon a close retentive soil.’’ 
his old Vines and planting young ones upon his renovated bor 3 
he cut back his mes and spread their roots all over the We 
der, ‘and covered them about six inches.” Although og 
Pontey isa large Nurseryman, and has multitudes of young Vio! 
im, he preferred his old plants, well knowing that ¥' 
plants would strike down their main roots to the bottom © 
new borders and run along them, if not into worse soil, 
said last week, These old Vines having formed all their ™ 
roots, will afterwards only form secondary ones to collect nour? 43 
ment, and after this nourishment is digested by the leaves ? 
leposited in these 1 
to have his Vine roots near the surface at Plymouth, how mo 
more ought this to be attended to at Inverness, where I firs 
the Vine? ‘This way of treating old Vines has been adopte!’ i. 
gardeners for years. Indeed many good gardeners say Gris 
never come to their true flavour until after the plants are ung 
transplanted; and few gardeners in these days will plant yorars 
Vines if they can get old ones ; buta Vine, like an Oak, at 20 Yenc’ 
old is comparatively a young plant. I recollect some 14 years si 
renew their age,” and sure enough he did. 
covered that he inarched his young plants on them as 00) 
they grew away freely. Now if you adopt my friend’s Pla je 
me urge you to keep the colar of the old plants well up abOve ve, 
soil; as if any part above the old roots is buried, it will inrines 
diately throw out roots, and these, like the roots of a youDs more 
will go down at once to the bottom of the border, and bein& ¢. 
active than the old roots will in time derange the experime?™” 
I.—FLOWER-GARDEN AND SHRUBBERY. 
nt. vincial 
rags 
prevent its flowering, which it does very freely when oD out 
room, Six weeks ago we had the half of its roots take” 
wt lan 
cast 
