THE GARDEN ALBUM AND REVIEW. 
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Iris Qatesi (reduced.) 
IRIS GATESI. 
This handsome “ cushion” or “Oncocyclus” 
Iris is a native of Armenia. In appearance it 
bears a great resemblance to the well-known 
I. Susiana, popularly known as the Mourning 
Iris owing to its dark silvery grey appearance. 
The rhizome of I. Gatesi is somewhat more 
compact, while the leaves are shorter, narrower, 
and of a deeper green than those of I. Susiana. 
The large flowers appear about June and are 
borne on stems 18 to 24 inches high. The 
drawing represents one about half natural size, 
but it is easy to distinguish the dark coloured, 
delicate, and yet conspicuous veinings and the 
blackish purple dots that decorate the creamy 
white ground. 
Iris Gatesi is one of the species that has 
been utilised with others of the Oncocyclus 
group for producing the charming new Irises 
of which a coloured plate appeared in our first 
number. To secure the best results with this 
class of Irises it is essential not to plant them 
too deeply; that the soil should be light, rich, 
and well-drained; that they should not be 
disturbed in autumn if possible; and that the 
roots be protected from cold rains during the 
winter months. - 
Lissochilus Horsfalli. —A few magni¬ 
ficent plants of this noble West African Orchid 
were shown recently at the R.H.S., by the 
Right Hon. Lord Rothschild, Tring Park, and 
received a First-Class Certificate. The plants 
were about 5 feet high, and had bright green, 
lance-shaped, plaited leaves, above which the 
white and purple flowers towered on stout 
scapes. 
AIR VERSUS SOIL. 
It is still a common belief that the great 
bulk of all plants comes from the soil, and this 
belief is considerably strengthened when first- 
class gardeners constantly recommend trenching 
or deep digging, as well as manuring. As a 
matter of fact, however, the great mass of 
tissue in a plant is secured, not from the soil, 
but from the atmosphere. I he old philoso¬ 
phers, including Aristotle, taught that all the 
nourishment of plants came from the soil 
alone. This doctrine was accepted without 
question for centuries. At last, a learned 
Belgian physician named John Baptist van 
Helmont, who was born in Brussels in 1577, 
entertained doubts as to the accuracy of this 
teaching. To settle the matter he commenced 
experimenting. He planted a willow, which he 
had previously carefully weighed, in a pot 
containing 200 lbs. of soil. He watered the 
plant daily with rain water. The willow 
flourished, and at the end of about five years’ 
cultivation he weighed the plant and soil again. 
The willow had gained i64lbs. in weight, but 
the soil had only lost two ounces! It was, 
therefore, obvious that Aristotle, and the 
others had been all wrong. It was impossible 
for the i64lbs. of wood, leaves, etc., to be made 
out of the two ounces of soil. Van Helmont 
was puzzled, and eventually came to the 
erroneous conclusion that the extra weight 
could only be obtained from the water he had 
given the plant. He had no idea of the 
numerous minute pores or stomata on the 
under surface of the leaves, nor of the fact that 
carbonic gas was absorbed from the atmosphere 
during, the day time, and oxygen liberated. 
This discovery was made 200 years later by a 
Dutch scientist, Jan van Ingenhousz, who 
published his researches in 1779. 
The practical value of this discovery is not 
always appreciated even by gardeners. From 
what has been said, it is obvious that the great 
bulk of a plant is secured from the carbonic 
acid g*as in the atmosphere by means of the 
leaves. It is essential, therefore, that plants 
should be allowed plenty of head room to 
enable their leaves to perform this important 
work, especially as there is a comparatively 
small quantity of carbonic acid gas at their 
disposal in the atmosphere, only 4 volumes 
out of 10,000. If this fact were better known 
and appreciated we should not see potatos 
planted about 12 or 18 inches apart, nor should 
we see plants of all kinds jumbled up so close 
together that most of their leaves are in shade 
and darkness, under which conditions it is 
quite impossible for them to secure little if any 
carbonic acid from the atmosphere. 
TRAVELLER.—Head Gardener, Scotch, 
resident in the West of England, is desirous of 
securing an appointment as Traveller to a 
good firm of Seedsmen ; energetic and reliable. 
Kennedy, 75, Oak Street, Abertillery, Mon¬ 
mouth. 
