334 
[ October 11,188#. 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
anythin? substantial to prove this statement. It is pure theory. He 
admits that it would be gross carelessness for a professional gardener to 
scald Black Hamburgh, but he does not add that it would be the same 
thing to scald Lady Downe’s. Every practical gardener knows that 
with the utmost care this Grape will scald more or less in the majority 
of cases in spite of every means of ventilation or care. 
Mr. Bardney will admit that scalding Black Hamburgh as badly as 
Lady Downe’s would be gross carelessness. Conditionally it is admitted 
both are produced by the same cause. Possibly they are, but it would 
require an extra amount of the “ same cause ” to scald the former as 
badly as the latter. This is the chief difference between your corre¬ 
spondent and myself. So we are nearly agreed, for I have not brought 
forward any theory as to the reason of scalding, but wished to show 
they could not be compared as equals in the evil. Attention is drawn to 
the unseemly mixture of Lady Downe’s in an early Hamburgh house. 
Hardly anyone can be more sensible of this fact than myself, but it is 
only one case of many that could be cited on this point. But under 
the treatment given there is no excuse for the one variety scalding more 
than the other if they are both as susceptible to the evil. Overforcing 
is, no doubt, the cause of many ills that affect our Grapes. But I fail 
to see that Lady Downe’s, grown as naturally as possible, can be over- 
forced systematically. If so, it takes very little forcing to injure them. 
I have seen Black Hamburgh forced very hard, but never remember 
seeing them scald. 
That Lady Downe’s will scald without the sun’s direct action I 
think all will acknowledge, for houses that are shaded will sometimes 
scald as badly as those that are not shaded, except by foliage. There is 
something different about this Grape ; it is either weak constitutionally, 
or it differs structurally, for the berries do not stand the same amount 
of treatment as the majority of other Grapes. When w T e get at the real 
cause of the scalding, then I think we shall find an infallible remedy, 
but at present, what appears adequate to prevent the evil in some places 
is totally inadequate in others. -James B. Riding. 
That this annoying phenomenon is more generally prevalent than 
the knowledge necessary to avert its disastrous effects the various 
opinions of numerous correspondents fully testify. Having had some 
experience in dealing with some rather persistent attacks I venture to 
submit the ideas I have formed as to its cause and prevention. 
Regarding the cause, I think we are all agreed that the wrong dis¬ 
position of heat and moisture are the predominant forces which produce 
the effect ; but in reference to the action of these agents there is, I 
perceive, much divergency of opinion. In the correct elucidation of 
Mr. Young’s proposition, “ AVhat., then, is the cause of moisture being 
condensed on the berries ?” will I venture to say be found the lever that 
will give the uninitiated power to cope with the difficulty. This corre¬ 
spondent's theory “ That an overheated atmosphere caused by the sun 
shining suddenly on the house without sufficient ventilation, as well as 
insufficient heat in the pipes to prevent the berries becoming cold,” may, 
to Mr. Bardney’s mind, appear somewhat vague, and possibly heterodox 
if he is a firm believer in “ somebody’s ” theory on the “ liquefaction of 
vapour.” That the writer of that useful pamphlet may be well versed in 
reference to the formation of dew on the open ground, and in that 
direction his theories may be infallible ; but when it comes to the 
natural action of air, heat, and moisture in an artificial structure like a 
glass house they may in many instances be at a discount. Condensed 
moisture on the berries of Grapes is due to a low temperature,” says Mr. 
Bardney, “ and the berries being naturally colder than the atmosphere 
they cool the air in contact with them, and the consequence is that some 
of the vapour it contains is quickly deposited. As the temperature rises 
the air takes up the moisture which it had previously deposited, and the 
result is evaporation. Instead of condensation taking place when the 
temperature rises evaporation takes place, and the air is charged with 
heated vapour that practically 1 stews ’ the berries unless means of 
escape for it have been provided.” This I take to be the gist of 
Mr. Bardney’s arguments, and in it I think we can trace a desire to prove 
the case by analogy with the generally accepted theory of the deposition 
of dew-viz., the cooling of an atmosphere laden with moisture, and 
consequently its inability to retain it suspended in an invisible form, 
hence it deposits in the form of tiny globules of water on points of leaves, 
grass, &c. This form of condensed moisture occurring in vineries and 
plant houses nearly every cultivator is familiar with, caused undoubtedly 
by eaily closing with sun heat and plenty of moisture being distributed, 
consequently a high humid atmosphere followed by a rapid fall and 
deposit of dew if there is insufficient heat in the pipes to maintain the 
temperature above dew point. But in all well-regulated vineries this 
shutting up with a strong sun heat should only be practised during the 
early part of the growing season, and then the advice to allow a low niaht 
temperature is open to grave question if this course is followed. The 
first part of Mr. Bardney’s quotation will he correct enough, “ Condensed 
moisture on the berries of Grapes is due to a low temperature,” but the 
second part, alluding to berries being naturally colder than the 
atmosphere and thereby favouring a deposit of dew, is altogether contrary 
to the present phase of ‘‘liquefaction of vapours,” as I cannot but think 
that if Mr. Bardney will recollect in cases where moisture has been 
condensed owing to a low temperature he must have observed the 
partiality the liquefied vapour has for points of leaves, tendrils, and 
other sharp protuberances. But it is not in this fact that injury is 
caused, he argues, hut when the temperature rises, and this moisture is 
again al sorbed or evaporated from the berries and the leaves, this 
vapour-charged and highly heated atmosphere “ practically stews the 
berries.” No mention is made as to how the leaves and tender shoots 
fare under this ordeal. Possibly Mr. Bardney’s theory on leaf-scorching 
is correct, which is, I believe, that such an occurrence cannot take place- 
if means are taken to insure the preservation of a moisture-laden 
atmosphere. We never hear of Cucumbers being injured by “stewing.” 
though they are compared to Grapes subjected by some successful 
cultivator to abnormally high temperatures. 
Again, why does scalding generally occur on the shady side and in 
the centre of the bunch ? If Mr. Bardney’s theory is correct all and 
every berry should fare alike ; also for a full and complete remedy a 
ready means of escape for the moisture evaporated by the sun raising 
the temperature is recommended, though some correspondents affirm 
that free ventilation was only partial in staying the mischief. To that 
I think we must look in another direction for the solution of the enigma. 
Mr. Young’s theory, as given at the commencement, though perhaps a 
trifle too concise, is, I am inclined to think, the correct one. The gene¬ 
rally accepted law of condensation may be right enough and work on 
exactly the same principle in the open as in a glass structure, but when 
we come to evaporation the artificial restrictions materially affect its- 
working. Under natural conditions scalding of fruits or scorching of 
foliage seldom or ever occurs owing to the freedom of evaporation of 
moisture deposited on vegetation. But under artificial treatment the 
case is different. The sun shining on the house raises the temperature, 
and evaporation takes place—that is, the heated air by chemical affinity 
absorbs moisture from surrounding substances up to this point. I agree 
with Mr. Bardney and somebody’s theory on the “ liquefaction of 
vapours,” but here I depart, owing to artificial means setting aside the. 
common rule of Nature. The sudden rise and compression in the tem¬ 
perature of a glass structure when closed, and sometimes even when 
ventilated, is very rare in Nature, therefore we may expect to find re¬ 
sults the causes of which are apparently obscure though natural enough 
when understood. This, then, is my theory, that a rapid rise of the 
temperature, owing to the sun shining suddenly on the house, enables 
the atmosphere to absorb moisture ; the berries which have arrived at a 
period of density of tissue are unable to heat so quickly, consequently 
by a law of Nature any object of a less temperature than the air it is 
surrounded by cools the air about it, so that if the air is charged with, 
moisture the influence of the cold body renders it incapable of carrying 
it, consequently it is thrown down or condensed on that body, as illus¬ 
trated by the objectional state of affairs known amongst Grape growers 
as “ sweating.” This moisture not being evaporated quickly becomes 
heated, consequently the scalding of the skin of the berry takes place. 
Why the berries are generally most damaged on the side opposite to that 
nearest the sun is a circumstance that is explained by the more rapid 
warming of their substance and their non-liability to act as re¬ 
frigerators. 
This, then, I think is the solution which was shadowed by Mr. Young* 
and the main difference between Mr. Bardney and the foregoing is in 
the way the moisture is condensed on the berries, but it is in the proper 
elucidation of this circumstance that enables us to propound a remedy, 
or, better still, a preventive. With Mr. Young I favour sufficient heat 
in the pipes to prevent the berries getting cold, and also to obviate a 
too humid atmosphere, and coupled with intelligent ventilation, Lady 
Downe’s or any other variety of Grape may be grown without any 
scalding taking place. 
As to some varieties of Grapes being more susceptible to this form of 
injury than others, I venture my humble opinion that all Grapes are 
liable to scald if proper precautions are not taken to prevent it, though 
some varieties more than others, owing to the physical structure of their 
berries, Lady Downe’s especially so, the large solid formation of its* 
seeds, and general dense construction, renders it unfit to withstand rapid 
changes of temperature. This is, I think, proved by the injury taking 
place during the stoning period, when the solidity of the berry is in¬ 
creasing, while at the same time the skin is in as tender a condition as 
previous to attaining this stage, and in many cases the treatment they 
receive in respect to damping down and closing being continued the- 
same as earlier in the season, consequently aggravating the evil. I am 
of opinion that if the treatment that is generally given when colouring 
commences—viz., more air and drier, but not necessarily a lower tem¬ 
perature, was put in force during stoning, scalding would soon be un¬ 
known.— M. Combe. 
Mr. Bardney does not strengthen his case in the least on the main- 
question at issue by his remark that his article was intended for the- 
young gardener and amateur. Mr. Bardney now says that he never sug¬ 
gested that these two varieties grown together in the same house would 
both scald, but he did say that it was just as easy to scald the Black 
Hamburgh as Lady Downe’s. I conclude by the above statement that 
he has had disagreeable experience in the scalding of the Black Ham¬ 
burgh ; if such is the case I would advise him to alter his practice. The 
“main points” which he thinks l, in common with your other corre¬ 
spondents, have overlooked, have not the least bearing on the portion 
of his article which I disputed. If he thinks he will succeed in con¬ 
vincing the readers of the Journal, he has a hard task before him. 
Surely he cannot be in earnest concerning the part of his article which I 
did not comment on, and which he says tells against me. As a matter of 
fact he has already had his answer when I stated that it “required gross 
carelessness to scald the Black Hamburgh.” Can Mr. Bardney prove 
that the Black Hamburgh will scald under the slight conditions which 
will scald Lady Downe’s? Your correspondent also professes to be 
amused at my allusion to the cost of Grapes, it being foreign to Grapes. 
