100 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
August 2,1894. 
After a few years blooming the flower scapes on Oncidium papilio 
become weak and hard and the blossoms smaller. This is a good 
time to remove these old scapes, as new ones will soon be produced 
to take their places. Where this Oncidium is grown on blocks the 
sphagnum may be allowed to grow freely at this season, as less 
attention will be needed in dipping or syringing. 
Semi-terrestrial Orchids, as Calanthes, Peristerias, Phaius, and 
Sobralias, may with advantage be given occasional doses of liquid 
manure. That made from cow manure and a little soot, well 
diluted and used at a temperature corresponding to that of the 
house the plants are growing in, may be used with safety once a 
fortnight. See that the plants are moist at the roots before this 
is given. _ 
Al l distichous-leaved Orchids, such as Saccolabiums, Yandas, 
and Angrsecums, require copious supplies of water at the root, 
and with the exception of Phalsenopsis, occasional sprinkling when 
the weather is fine. Stanhopeas, too, delight in frequent dewings 
over the foliage, this treatment serving to keep red spider in check. 
Gradually diminish the supply of water to Thunias, and allow 
plenty of air. A frame as advised for Dendrobiums will now be a 
suitable position for these Orchids. Odontoglossum vexillarium is 
now on the move, and the young growths must be kept free from 
thrips. Our plants have not been taken to the cool house this 
season, except for a few weeks when in flower. Cleanliness and a 
sweet and substantial root-run are the most important points to be 
studied with this Orchid, and given these the growth is finer and 
the flowers more freely produced in an intermediate or Cattleya 
temperature than in the cool house. 
A few cool house Orchids are approaching the completion of 
their growth, and especial care is needed that the plants do not 
suffer from want of water. Pseudo-bulbs that finish prematurely 
usually commence to grow before the spikes are formed, and these 
latter are weaker in consequence, or altogether wanting. PJeiones 
that have been growing in an intermediate house must, as soon as 
the pseudo-bulbs are fully developed, be returned to the cool house. 
They must be carefully watered now, and less will be required as 
the foliage turns colour. Treat Lycaste Skinneri generously as 
regards water, as it is impossible to grow this species too strongly. 
Maintain a sweet atmosphere by continuing to keep all pots, stages, 
and glass clean. Any dead leaves or spent pseudo-bulbs must be cut 
clean away with a sharp knife. Keep a sharp look out by night 
and day for insects on the young foliage, or slugs and woodlice at 
the roots, as much mischief may be done at this season by in¬ 
attention in this respect.—H. R. R. 
THE NUTRITION OF ROOTS. 
Mr. Gilmour (page 75) evidently thinks he has knocked Mr. 
Raillem out; and before or while claiming the victory calls upon 
his defeated opponent to again come up to the line ; but does Mr. 
Raillem feel himself the defeated one ? That is the question. Mr. 
Raillem did no harm in asking or placing before the readers and 
critics of the Journal four numbered paragraphs (page 388), 
one part of which was someone else’s and the other part his 
own. It appears that he bases his own conclusions upon deduc¬ 
tions drawn from that portion supplied by others, and has run off 
the line. 
Moisture which exists low down in the soil when the surface 
becomes dry by excess of heat or drought becomes rarified and is 
diffused, carried by capillary attraction to the surface. Can this 
moisture be called water ? can it be called vapour, while one is a 
liquid and the other an invisible compound ? I say no. It is a 
condition between the two capable of dissolving—more so than 
actual water—soluble elements and compounds which can be assi¬ 
milated by the plants. Do not understand me to say water applied, 
or which falls through rain, or is forced up, as in springs, is not 
water ; nor that the roots cannot make use of it in that form ; nor 
yet that it will not dissolve soluble and insoluble plant food present 
in the soil. I do not say that. We are obliged to say what we do 
not mean as well as what we do in this “ jumping generation.” 
I will put it in this form. If a piece of sugar is saturated with 
water, the latter would still be in a liquid form. If a few 
drops are dropped upon a large piece of sugar and get diffused the 
drops of water will be water no longer, but moisture, not actual 
vapour nor yet liquid. Mr. Raillem’s authority was wrong no 
doubt in saying plants could not assimilate water, and I think 
“ J. A., Kew ” (^page 444), hits the mark by saying that the sus¬ 
pended moisture in the air or in the soil is converted into a liquid 
condition under certain conditions. My impression has always been 
that the roots being cooler than the soil the air condenses this 
moisture or the vapour into water, and assimilates it with any food 
that may be in solution. 
I will say that in paragragh 1 (page 388) Mr. Raillem was 
wrongly informed ; paragragh 2 he is practically right; paragraph 3 
he is wrong by no fault of his own ; and upon paragraph 4 
he is right as far as he goes—that is, moisture which rises as 
long as it is in the soil holds soluble mineral constituents, and that 
plants will receive benefit from manure beneath them even when 
they do not send roots down into that manure. In his last 
paragraph, not numbered, he states that it is not generally under¬ 
stood that the roots of plants only imbibe moisture as it is in the 
process of being evaporated, and asks if it is true. If he leaves the 
“ only ” out I shall say it is true, and defy contradiction. 
I will finish with Mr. Raillem with his saying that the roots 
have the power by mechanical decomposition of getting at that 
vaporous form of liquid. What vaporous form if water is decom¬ 
posed ? Where is the liquid ? The resultant matter comprise gases, 
of which oxygen is one and hydrogen is the other. That the roots 
can decompose water and appropriate either of these gases is true, 
but neither would be liquid nor yet capable of holding in solution 
plant food of any kind. I therefore must say the authority has 
done Mr. Raillem no good ; but surely such an able pen can set 
himself right though he has an opponent worthy of his steel. 
For the information of Mr. Gilmour I will say that there is a 
state in which oxide of hydrogen exists between water and vapour. 
At the boiling of a kettle the water, which is liquid, is converted 
into vapour, and if anyone looks at the spout out of which it passes 
it will be noticed that the vapour is invisible ; an inch or so away 
from it the condensed vapour is visible. This is not water nor 
vapour, as one is liquid and the other is invisible, but consists of 
small bubbles. Again, it passes into an invisible form called 
vapour. If a cold substance is placed in contact with the steam, 
then it will be converted into a liquid form called water. The 
clouds are made up of similar small bubbles, which by the action 
of sun and light is capable of passing into vapour, or by coming in 
contact with a cold stratum of air is converted into water. I do not 
say that the basis of vapour, steam, clouds, snow, ice, and Scotch 
mist is not water, but it is water in all its various forms. At 
this I will leave it to Mr. Gilmour and Mr. Raillem to set me 
right where I am wrong, trusting they will not fail to set them¬ 
selves right at the same time.— Geo. A. Bishop, Wightwich Manor 
Gardens. 
CHLOROSIS OR YELLOWS IN PEACH TREES 
AND TOMATOES. 
{Concluded from page 74.) 
Chlorosis almost invariably shows itself where Peaches attain 
their greatest size and perfection, and that is where the soil is good 
and the subsoil moist. No one cares to have his name mentioned 
in connection with this malady, otherwise I could refer to several 
places where it has appeared and been cured without recourse to 
lifting, and the costly process of bringing in virgin loam ; therefore, 
I must trouble my readers with a few figures relating to Peach 
trees free from and afflicted by yellows. 
Analysis op Peach Branches by Kedzic. 
Ash constituents. 
Hea'thy. 
Diseased by 
Yellows. 
Silica, SiO^ . 
1-21 
1-.40 
Oxide of iron, . 
0-92 
0-84 
Lime, CaO . 
43-67 
45-02 
Majnesia, MgO. 
2-53 
2-40 
Potash, KgO . 
Soda, Na^O . 
Phosphoric acid, PgOj. 
7-07 
4-93 
1-88 
2-33 
7-20 
6-03 
Sulphuric acid, SO^ . 
0-54 
0-83 
Carbon dioxide, CO^ . 
34-71 
35-85 
Chlorine. 
0-07 
0-11 
Moisture and loss . 
0-30 
0-26 
Total 
100-00 
100-00 
The deficiencies of the soil (the constituent elements of the 
branches being taken as a criterion) are not very striking in the 
case of the diseased as compared with the healthy branches, yet afford 
sufficient data for arriving at a certain conclusion. In the diseased 
branches there is a deficiency of 3' 14 of potash, which it is easy to 
supply by wood ashes, say 1 peck per rod (30J square yards), next 
phosphoric acid, 117, and this could be furnished by applying 
7 lbs. of Thomas’ phosphate per rod or 3^ pounds of steamed bone 
