394 THE COTTAGE GARDENER AND COUNTRY GENTLEMAN'S COMPANION, March 10, 1857. 
highest. Hales computed the perspiration of plants to be 
seventeen times more than that of the human body. He 
found that a Sunflower and a Cabbage lost respectively about 
1Mb. weight of moisture thus thrown off" by perspiration. 
In many plants the orifices through which these perspiratory 
processes are carried on are exceedingly minute, so as scarcely 
to be discovered with glasses of great power, such as in the 
Myrtle; in others they are much larger, as in the Oleander. 
In the Hydrangea more than 100,000 orifices have been 
counted in the space of a square inch. We all know what a 
quantity of water that plant requires in fine, bright weather. 
That not mere outside, but also under-side cleanliness, is 
needed will be further demonstrated by the fact, that though 
many plants have these perspiring orifices on both sides of 
the leaf, yet in a great number of plants they are confined 
chiefly to the under side of the leaves. Plates of glass, tin, 
zinc, or other metals, have been placed to the under side of 
strong-growing young Vine leaves, Hydrangeas, &c., in a 
bright, sunny day, and they soon became moist with dew. 
When placed on the upper side none was formed. This, 
however, is not the case with all plants. A great exception 
exists in all aquatic plants whose leaves repose on the 
water. In such leaves the perspiring orifices are uniformly 
on the upper side. Keep them reversed and they soon 
decay. In aquatics whose leaves rise freely above the water 
the perspiring orifices, as, I believe, in the bulk of land 
plants, are found chiefly in the under side of the leaves. In 
experiments with cut twigs and leaves placed in water it was 
found that many kept alive about an equal period whether 
the upper or lower side of the leaf touched the water. In 
the majority of instances, however, they remained fresh the 
longest when the upper side touched the water. One fact 
more. Evergreens, and especially those with thick-skinned, 
shining leaves, like a Laurel or a Camellia, perspire less 
freely than a deciduous plant when its leaves are young and 
growing freely. I have varnished the back of Vine, Holly¬ 
hock, and Sunflower leaves with a thickish solution of gum 
arabic, glue, &c., and they soon became unhealthy and yel¬ 
low. In cases where the covering had cracked and pieces 
fallen off they suffered but little. The others, deprived of 
the power of cooling themselves by perspiration, were par¬ 
boiled in their own juices. These remarks will show the 
importance of the sponge and the syringe in keeping all 
parts of window plants thoroughly clean. 
Aquariums. —As 1 have just alluded to aquatics, and as 
aquariums are becoming fashionable, I may mention that 
aquatic vegetation, in addition to lending its influence to 
purify the atmosphere, does also a great deal to purify the 
water, and render it salubrious to the fishes and other 
animals living in it. Had I an aquarium and could get 
nothing else, I would have Duckweeds and Water Crowfoots 
growing freely over it. Were I thirsty and coming to two 
ponds in a moorland waste, the one clear of vegetation and 
the other covered with Duckweed and Ranunculus aqualilis, 
I Avould go to the latter, and lap away until I was satisfied. 
Succulent Plants. —Other things being equal, the more 
freely plants perspire the more attention will they require, 
especially when in such artificial circumstances as growing 
in a window. When growing naturally in the open ground 
the rate at which a plant perspires is of less consequence, 
because there is no limit to the space from which its roots 
can absorb moisture to supply the demands made by a free 
perspiration. As succulents perspire very little, and absorb 
moisture from the atmosphere very freely, rendering them 
but little dependent on moisture at the roots, the vvliole tribe 
of Cantus, Sempervivums, Mesembryanthemums, &c., are 
peculiarly fitted for amateurs vvho have to be much from 
home. The chief things are plenty of sunlight, an atmo¬ 
sphere not over dry, a temperature securing safety, and the 
stems free from dust and other incrustations. In conse¬ 
quence of perspiring but little they require little watering at 
the roots, unless in the height of the summer, and at all 
times will sooner suffer from too much than from too little. 
Protection from Dust. —In every room in which plants 
are kept there will be dust, less or more, and especially when 
a general dusting and cleaning-up take place. Here, as well 
as in many other cases, prevention is better than cure. 
Many plants are so downy that it is next to impossible to get 
all the dust from them when once it has found a lodgment. 
To avoid this some of our friends remove the plants out of 
the room when dust is likely to be disturbed; others have 
their plants in a stand, with open sockets at the corners, 
in Avhich the ends of iron hoops, or hoops of stout hazel rods 
kept on purpose, are fixed, and a clean cotton cloth thrown 
over and tied beneath keeps them quite clean. When the 
dust left has quietly settled down again the cloth is care¬ 
fully removed and shaken out of doors. The same cloth, 
used in a similar manner, is also useful on a very cold 
night. 
Clean Windoavs. —I have no occasion, after what has been 
said, to utter a Avord about keeping the pots clean and free 
of all green, slimy, fungous vegetation. I need not add a 
word as to keeping window-sills and plant-stands scru¬ 
pulously clean by frequent Avashings. I am sure that those 
avIio have read thus far will require no urging to keep their 
glass clean, free of dust, fly markings, and pretty spiders’ 
webs in the corners. Crusted Avindows are more pardonable 
in towns ; but there, on that very account, clean AA’indows are 
the more valuable for keeping people cheerful and the plants 
healthy. A Avindow through Avhich you cannot see is enough 
to give any one a fit of the blues. In answer to many in¬ 
quiries as to whether plants in Avindows could be grown 
under such and such glass, and covered and fluted in a 
certain way to prevent people seeing through it, &c., I reply, 
that the best plate or best croAvn glass is what I Avould prefer 
for a sitting room, alike for my own comfort and the health 
of window plants. Then, in dull weather, the plants will 
receive all the light possible. In sudden changes in spring 
from dull to bright, and in very bright weather in summer, 
there may frequently be more light and heat than the plants 
will quite relish; but then a pretty thin muslin curtain Avill 
place the plants quite at their ease, or you might remove 
them farther into the room. I believe that glass might be 
slightly tinted with green or violet, so as not to injure plants 
inside of it, and people could not easily see through it; but 
neither Avould you if you wished to look out. Rough and 
fluted glass would permit enough of light to pass, and 
exclude a portion of the heat; but there is no seeing through 
it comfortably. A lady saw a gardener sizing and whitening 
his front sashes, and she Avent home and did the same with 
her window, and did not like the result. Her plants became 
weak and drawn. She forgot that the gardener admitted 
light from above and behind, though he shaded the front. 
In her case, the Avindows being shaded, all the light Avas 
shaded. 
Although, then, things may be grown freely behind 
ground, rough, or fluted glass of good quality, yet for window 
plants I prefer clear and clean glass, and a muslin curtain 
Avhen necessary. Of aspects, all things considered, the south 
is the best, then AA r est and east; the north is the worst, but 
in such an aspect plants will remain longest in bloom. 
Irritability of Plants. —In alluding even thus inci¬ 
dentally so much to cleanliness, I give it a prominent place 
in the elements of success. A great point is gained when 
we come to look upon a plant as an organised existence very 
different from a clod or a stone, and Avith powers of irritability 
frequently approaching that of sensation in animals. I have 
seen many gaze in wonder at the mysteries of the Sensitive 
Plant (the Mimosa pudica), whose leaflets droop at the 
slightest touch, and from that day become more earnest and 
careful cultivators. I have seen dozens of boys and girls j 
watching the leaflets of various Acacias, the Cassia corymbosa, \ 
and even the common French Bean, folding back and going j 
to sleep at night, and I have been assured that they in i 
future experienced a love and a sympathy for plants Avhich , 
they never felt before. When we find our young people 
talking of the shaking vagaries of the side leaves of the 
Hedysarum yyrans, while the terminal leaflet alternately 
rouses itself into wakefulness and then lulls itself again to 
drowsy repose; when you hear them making out lists of 
flowers that open and shut at certain hours and in certain 
states of the atmosphere, some at mid-day and others at 
midnight, or of others that throw off their perfume in com- j 
pliment to the sun, while others hoard up such treasure in 
honour of the stars and moon ; when you hear learned dis¬ 
cussions on how mineral and vegetable poisons exercise a 
similar and as destructive an influence upon plants as upon 
animals; and when you listen to expressions of delight at 
the beautiful harmony and reciprocity existing between the 
vegetable and the animal world, then, indeed, may we expect 
