668 
THE GARDENING WORLD. 
July 3, 1897. 
Crotons. 
About ioo of the best varieties of this useful class of 
plants are kept in stock, including the pick of the 
old and the newest favourites. Amongst them are 
such favourites as Aigburthense, Chelsoni.Formosum. 
and Golden Ring, the latter having curled and 
twisted, green and yellow leaves. Prince of Wales 
is also curly and yellow, but ultimately red. 
Thompsoni has broad, obscurely three-lobed leaves, 
variegated with yellow. The best of the broad¬ 
leaved type is Reidi, with olive-green leaves and red 
veins. The top leaves are yellow, changing to 
orange, and then to carmine. Aigburth Gem is one 
of the Interruptum type, with green, yellow, and 
crimson leaves in varying proportions. The general 
aspect of Davisi is yellow. Mr. Blause is a broad¬ 
leaved type beautifully variegated with yellow. 
Prince of Orange is a slow grower, with green and 
yellow leaves, but often wholly yellow. The narrow 
leaves of Flambeau are yellow with a red midrib, 
but ultimately are very red. Princess of Wales is a 
showy variety with very long leaves of medium 
width, and creamy-yellow with green edges. Very 
distinct in its way is Delight, having short, wide 
eaves of an ivory-white along the centre, though the 
top leaves are generally wholly of one colour. 
Countess is also very choice, being about equally 
marbled with green and yellow, and often distinctly 
blotched with the latter colour. The above are only 
a few of the choicer Crotons to be seen in the Mor- 
land Nursery ; but there are few of any note which 
Mr. Bause cannot supply. 
Pitcher Plants. 
Besides those already mentioned, there are 
numerous other species, varieties, or hybrids of 
Nepenthes accommodated in various houses, and 
mostly suspended over small Palms. N. mixta is 
boldly and handsomely blotched with crimson. N. 
Curtisii is of a dark chocolate-crimson, marbled 
with light green. Another magnificent hybrid is N. 
dicksoniana, with long pitchers handsomely blotched 
with light crimson. Long, narrow, and pale coloured 
pitchers are produced by N. Courtii. The rare N. 
northiana and N. Rajah are also cultivated here. 
Numerous sorts are also to be seen in the propa¬ 
gating pit including the rare N. Veitchii and the still 
rarer N. sanguiuea. The former has green, hairy 
pitchers with a prominent collar. The latter is a 
most handsome pitcher of great size, and uniformly 
of a beautiful bright red ; the upper part of the 
pitcher internally is nearly white variegated with 
soft purple. Of smaller size but richly coloured are 
N. Morganiae, N. Curtisii superba, and N. formosa ; 
the latter resembles N. Morganiae in shape, but is 
heavily blotched with crimson on a white ground. 
The curiously inflated pitchers of N. Burkei excellens 
are notable for their broad, ridged, red-brown collar. 
Bertolonias, &c. 
Some handsomely grown plants of Bertolonia have 
at one time or other been brought before the public 
from this nursery. Most if not all of the varieties 
in cultivation have been tried here, and a selection 
of all the best made. The lightest variety is 
argyroneura, having large, light green leaves lined 
with white veins and marked with white spots. 
The richest-coloured variety is Souvenir de Gand, 
the long nerves of which are of a deep carmine-red. 
It grows rather too slowly to meet the demand for 
it. Scarcely less handsome is the large-leaved 
Comte de Kerchove, having bright rosy-red veins 
and spots. A pleasing light variety is Madame Van 
Geert, the veins of which, large and small, as well 
as the spots, are pink. Madame E. Pynaert on the 
contrary approaches Souvenir de Gand in having 
rich carmice-rose nerves and spots. The same may 
be said of Van Houttei, which has carmine-red 
nerves and numerous small spots. Punctatissima is 
totally distinct from either of the above in being 
dark olive green, covered all over with isolated 
white spots; while Punctatissima rosea is 
characterised by rosy spots. A pleasing light variety 
is Madame Alfred Bleu, having broad leaves lined 
lengthwise and crosswise with silvery-pink, and 
spotted with the same colour. Triomphe de l'Ex- 
position has leaves of a rosy-red hue, splashed in 
places with olive-green. 
A little group of Anoectochilus represents all the 
Orchids we noted in the nursery They are grown 
solely for their foliage. The golden tracery upon 
the leaves of A. Petola is remarkably fascinating. A. 
sanderianus in some respects is not unlike it, but it 
varies considerably according to treatment. The 
olive leaves of A. discolor are handsome, but the 
flowers are also pretty. The velvety-olive leaves of 
A. lowianus also make it a favourite with growers. 
The Musa-leaved Heliconia illustris rubricaulis is 
very handsome in certain stages both on account of 
its red and green leaves, and polished dark red leaf¬ 
stalks. 
-•*—- 
CHEMICAL COMPOSITION OF 
CATTLEYA. 
Dear Mr. Veitch, 
I have put together a few observations on 
the chemical composition of the Cattleya, together 
with some suggestions as to its food requirements, 
which I trust may be of some interest to yourself 
and to the members of tne Orchid Committee. 
In the Gardeners' Chronicle of February, 1894, there 
was an article on the chemical composition of 
Cattleya labiata, and also giving the analysis of rain¬ 
water in temperate and tropic climates, which 
showed a large increase in the amount of nitric acid 
in the rainfall of the tropics compared with 
temperate zones. 
Country. 
Authority. 
Milligrms. 
Liebfrauenberg (Alsace) , 
France 
Boussingault 
O 18 
Rothamsted, England.. 
Lawes andGilbert 
0'42 
J ava 
Homans 
230 
Isle of Reunion . , 
Raimbault 
265 
This is as may be expected, for it is well known 
that thunder rain contains nitric acid, derived from 
the rapid oxidation of the nitrogen of the atmos¬ 
phere by the electric discharge, combining imme¬ 
diately with the pure ammonia in the atmosphere, 
forming ammonia nitrate. 
In connection with this subject it is well to take 
into account the chief constituents of the air. 
Professor Frankland published in the Journal of the 
Chemical Society (vol. xiii.) the results of analysis 
of the composition of airs from various sources, 
which demonstrated that the composition of the 
atmosphere exhibits certain fluctuations, confined, 
however, within very narrow limits. The air near 
the sea contains about the same proportion of 
carbonic acid as that resting over land. The sea air 
was richer both in carbonic acid and oxygen by day 
than by night. 
- 
Average by Sea. 
New 
Granada 
Bogota. 
Day. 
Night. 
Dry 
Season. 
Rainy 
Season. 
Nitrogen 
Oxygen 
Carbonic Acid 
78886 
21 060 
•O54 
79006 
20 961 
033 
79946 
21*014 
•O4O 
78932 
21022 
*046 
78966 
20-996 
•038 
100*000 
100*000 
100*000 
IOO OOojlOOOOO 
Chamonix, 
3,000 feet. 
At the Grand 
Millets, ii.ooo ft. 
Mount Blanc 
15.732 feet. 
Nitrogen 
79086 
7908; 
78-9S9 
Oxygen .. 
Carbonic 
20 881 
20802 
20-950 
Acid .. 
•063 
III 
•061 
100*000 
100 000 
IOO 000 
The carbonic acid in the atmosphere appears to 
increase with altitude to attain its maximum at 
11,000 ft., and then again diminishes in quantities 
above that height. 
In the neighbourhood of our large towns the 
atmosphere is injuriously affected by the products of 
the combustion of coal, in the form of sulphurous 
and sulphuric acid aDd ammonia, and in some places 
— for instance, the Tyne and Clyde—by chlorine 
given off from the chemical works. There is also 
given off some of the more volatile petroleum oils, 
which form a greasy slime, which in fogs is deposited 
on the glass of our planthouses, and falling upon the 
leaves of the plants, interferes with their power of 
osmosis and exosmosis so necessary for their well¬ 
being. 
I have myself noticed that the quantity of ammonia 
in the atmosphere was subject to considerable 
variation ; the greatest amount was detected on days 
when the electric currents were feeble or totally 
absent. I have also observed hit the amount of 
oxidisable matter present in the atmosphere had nc 
relation to the quantity of ammonia present. 
I think it is probable that the relation of ammonia 
to carbonic acid has a considerable influence upon 
the growth of epiphytal Orchids. This is the 
probable cause that many Orchids—such as Onci- 
dium varicosum on the one hand, and Phalaenopsis 
on the other—cannot be kept in vigour for any length 
of time in this country. 
The analysis of old and new pseudobulbs shows 
that there is less mineral matter in old bulbs when 
compared with the new. Apparently these plants 
have great difficulty in obtaining the earthy salts, 
and are, therefore, obliged to withdraw from the old 
bulbs some portion of their earthy constituents. 
We know that allowing the flowers to remain on the 
plants until they have withered is followed by the 
shrivelling of the pseudobulb and with the exhaus¬ 
tion of the plant ; the better the variety the more 
delicate the constitution of the plant and the greater 
the exhaustion caused by flowering. 
Old 
Pseudo-bulbs. 
New 
Pseudo-bulbs. 
Dry substance, per cent. .. 
9 12 
8 07 
Nitrogen, per cent.. .. 
Mineral matter (ash), per 
1*21 
114 
cent. . 
0*41 
063 
Constituents of the ash in TOO parts. 
Potash carbonate .. 
• • 
2990 
3069 
Lime carbonate 
* • 
52*02 
3523 
Magnesia carbonate 
12 05 
I 4'47 
Lime phosphate 
3'42 
1068 
Iron oxide .. 
016 
0*17 
Silica 
2*42 
8-77 
It occurred to me that it would be desirable to find 
out which, if any, of the earthy constituents were 
removed from the pseudobulb by the flowers. For 
this purpose I sent up to my friend, Prof. Ogston, a 
large number of fresh-cut blooms of the largest and 
best varieties in my collection of Mendelii, Mossiae, 
and Laelia purpurata. 
The analysis of the fresh-cut Cattleya flowers 
gave :— 
Water .. .. .. .. .. 8427 
Vegetable substance .. .. .. T 3 ' 7 2 
Ash soluble .. .. .. .. i'i8 
Ash insoluble .. .. .. .. 0 83 
10000 
The percen¬ 
tage compos¬ 
ition of fresh 
cut flower. 
Percentage 
composition 
of dried 
flower. 
Percentage 
composition 
of the incin¬ 
erated ash. 
Water 
84-270 
_ 
— 
Organic matter .. 
13720 
87-21 
— 
Phosphoric acid .. 
•058 
39 
3-10 
Potash 
634 
3IS 
25*00 
Lime 
■348 
184 
I 4 ' 4 ° 
Magnesia .. 
*120 
*6o 
471 
Sulphuric acid .. 
■034 
■17 
1 35 
Silica 
■164 
■57 
4-50 
Carbonic acid, iron 
soda, alumina .. 
•702 
6 03 
4694 
100*000 
100*000 
100*000 
The carbonic acid in the ash was originally 
present in the bloom as organic compounds (nitro- 
hydro-carbons) combined with the potash, lime and 
magnesia. 
I do not, at present, see in what manner the 
epiphytal species in their native habitats obtain the 
alkaline and earthy salts, especially the silica, which 
is not easily soluble, and does not exist in a soluble 
condition to any large extent in any soil. 
I may mention in passing that chlorophyll 
(C 0 , H 9 , N 0 4 ) is the green colouring matter of plants. 
Ammonia and nitric acid salts appear to promote the 
combination of nitrogen with the hydrocarbons in 
the formation of this substance, but the absence of, 
or the exposure of plants to, an excess of sun-light 
seems to interfere with its formation. It may be that 
under these conditions another product, with a 
formula of C 19 , H 20 , N 0 3 is formed. 
Cyanine and Xantheine, the colouring material of 
flowers, are closely allied ■ to Chlorophyll. Cyanine 
is found in red and blue flowers ; in the former the 
