102 
THE FLORIST AND POMOLOGIST, 
[ July, 
them, a little cow-dung, dried and pulverised, 
or wanting this, a little dry liorse-dung. We 
think that, in this case, the addition of a little 
solid manure to the compost can only be of 
minimum utility. Orchids, whether terrestrial or 
aerial, are planted in a compost of materials 
which are very permeable, and through which 
the water one pours so profusely over them filters 
freely. It is impossible but that the little nitro¬ 
genous matter introduced with the cow-dung 
should be in a very short time absorbed or 
hurried away by the water, and after that its 
action can last but a very limited time. It 
seems to us that if a manure can be useful, and 
we do not doubt that it might be so, it would 
be necessary to give it not once in one or two 
years, at the time of potting, but now and 
then, in the liquid form, or even each time one 
waters, but then in very small quantities. 
But the epiphytes ? Is it sufficient, in order 
to give them all the vigour desirable, and to 
obtain from them a luxuriant flowering, to treat 
them, as is customary, in a good structure, 
with heat, water, &c., in pots half-filled with 
sphagnum and other matters ? And on what 
do those feed which are grown on wood ? Will 
the captive atmosphere of the house, saturated 
with water by vaporisation, be worth the free 
air of the virgin forests, charged with the 
gaseous products of their decomposition, for 
the food of the epiphytes ? We may be allowed 
to doubt it. Orchids mostly belong to regions 
where life is in the highest degree of intensity, 
where plants die on the spot, where the de¬ 
composition of organic matters is incessant and 
considerable. The atmosphere of these forests 
is necessarily charged constantly with the gases 
which this transformation produces ; and that 
it is these gases, combined with the rains, which 
maintain the life of the plants, of those espe¬ 
cially which borrow nothing from the ground, 
it is not possible to retain a serious doubt. 
But if the same plants, cultivated in our 
houses, have neither the azotised rains, nor the 
gases, nor the dust of their native place, is it 
not possible to supply them artificially? We 
must admit that certain data are wanting to 
fully resolve this question. What is the chemi¬ 
cal composition of orchids ? Is it the same in 
all ? Are the same elements found in equal 
quantities in all their parts ? For example, is 
the composition of the floral organs identical 
with that of the stems, pseudobulbs, and 
leaves? If not, the manure might be modified, 
so that it might be used according as the plant 
develops stems or flower-stalks. In the mean¬ 
time, and since one cannot dispute that epiphy¬ 
tal Orchids cultivated in our houses do not find 
there exactly all the elements on which they 
ought to feed, by what means can one provide 
enough for their urgent necessities ? 
At the Botanical and Horticultural Congress 
of Bruxelles in 1870, this interesting question 
was raised by M. de la Davansaye. This distin¬ 
guished amateur, in cultivating bromeliads and 
orchids, had placed in his houses gutter-pipes 
wherein circulated water into which a volatile 
nitrogenous substance had been thrown, and in 
this way he had obtained extraordinary results. 
The black soap used in the water with which 
he washed the leaves of his palms had been 
very favourable to them. M. Beiclienbach, 
the learned orchidologist, has related that he 
had seen in an orchid-house an extraordinary 
development, obtained by a procedure which 
had been kept secret, but which he had dis¬ 
covered consisted in putting manure on the 
pipes at night; but the plants thus forced to 
excess had a very short duration. Professor 
Edouard Morren, in cultivating these epiphytes 
in his little orchid-house, adopted the plan of 
depositing in one corner of the house a piece 
of carbonate of ammonia of the size of a small 
nut, which becomes volatilised in about eight 
days, and furnishes the atmosphere of the 
house with a supplement of carbonic acid, and 
especially of ammonia. 
Quite recently, M. le Comte du Buysson lias 
published in the Flore the results of his ex¬ 
periences in administering to epiphytal orchids 
manures mixed with the water used for syring¬ 
ing. That to which he gives the preference is 
guano of good quality, of which he uses a 
gramme (nineteen grains) to about a quart of 
water. The mixture is prepared the previous 
evening, well stirred, and then allowed to settle, 
and he strongly advises that this proportion 
should not be exceeded. With this he syringes 
his Orchids all over once a week during their 
growth. The leaves are not stained by its use. 
Underthis treatment, he says, his plants have be¬ 
come almost unrecognisable, and some young 
subjects have flowered which, without this aid. 
would have required years of growth. Two 
drops of ammonia in about a quart of rain¬ 
water have also produced excellent effects. 
Great interest attaches to these experiences 
made by conscientious amateurs, in the face of 
which one cannot doubt that the dispersion of 
