GRE 
to a different degree of warmth, which, together with 
the Green-houfe, will be fufficient to maintain plants 
from all the feverai countries of the world ; and with- 
out having thefe feverai degrees of warmth, it will be 
impoffible to preferve the various kinds of plants from 
the feverai parts of Africa and America, which are 
annually introduced into the Englifh gardens ; for 
when plants from different countries are placed in the 
fame houfe, fome are deftroyed for want of heat, while 
others are forced and fpoiled by too much of it; and 
this is often the cafe in many places, where there are 
large colleflions of plants. 
In the building thefe wings, if there are not fheds 
running behind them their whole length, the walls 
fhould not be lefs than three bricks thick; and if they 
are more, it will be better, becaufe where the walls 
are thin, and expofed to the open air, the cold will 
penetrate them, and when the fires are made, the heat 
will come out through the walls, fo that it will require 
a larger quantity of fuel, to maintain a proper tem- 
perature of warmth in the houfe. The back part of 
thefe houfes having Hoping roofs, which are covered 
either with tiles or Hates, fliould alfo be lined with 
Reeds, &c. under the covering, as is before directed 
for the Green-houfe, which will keep out the cold air, 
and fave a great expence of fuel ; for the clofer and 
better thefe houfes are built, and the glaffes of the 
Hope, as alfo in front, well guarded by Abutters, or 
Reeds in hard froft, the lelstuel will be required to 
warm the houfes ; fo that the firft expence in building 
thefe houfes properly, will be the cheapeft, when the 
after-expence of fires is taken into confideration. 
The Hoping glaffes of thefe houfes Ihould be made 
to Hide and take off, fo that they may be drawn down 
more or lefs in warm weather, to admit air to the 
plants ; and the upright glaffes in front may be fo con- 
trived, as that every other may open as doors upon 
hinges, and the alternate glaffes may be divided into 
two°; the upper part of each fhould be contrived fo as 
to be drawn down like faflies, fo that either of thefe 
may be ufed to admit air, in a greater or lefs propor- 
tion, according as there may be occafion. 
But befides the Conservatories here mentioned, it will 
be proper to have a deep hot-bed frame, fuch as is 
commonly ufed to raife large annuals in the fpring, 
into which may be fet pots of fuch plants as come from 
Carolina, Virginia, &c. while the plants are too fmall 
to plant in the open air, as alfo many other forts from 
Spain, &c. which require only to be fcreened from the 
violence of frofts, and ihould have as much free air 
as poffible in mild weather ; which can be no better 
effected than in one of thefe frames, where the glaffes 
may be taken off every day when the weather will per- 
mit, and put on every night ; and in hard frofts the 
glaffes may be covered with mats, Straw, Peas-haulm, 
or the like, fo as to prevent the froft from entering 
to the pots to freeze the roots of the plants, which is 
what will many times utterly deftroy them, though a 
flight froft pinching the leaves or fhoots, very feldom 
does them much harm ; if thefe pits are funk a foot or 
more, below the furface of the ground, they will be 
the better, provided the ground is dry, otherwife they 
muft be wholly above ground ; the Hides of this frame 
fliould be built with brick, with a curb of wood laid 
round on the top of the wall, into which the gutters, 
on which the glaffes Hide may be laid ; the back w r all 
of this frame may be four feet high, and two bricks 
and a half thick, the front one foot and a half ; the 
' width of the infide of the frame about fix feet, and 
the length in proportion to the number of plants to 
be containd therein. 
GREWIA. Lin. Gen. Plant. 914. This genus of 
plants was conftituted by Dr. Linnaeus, who gave it 
this name in honour of Dr. Grew, F. R. S. who pub- 
Lfhed a curious book of the anatomy of plants. 
The Characters are, 
The flower hath a thick leathery empalement , compofed of 
five fpear-jhaped leaves , which are coloured , and fpread 
open. ' The flower hath five petals of the fame form , but 
fmaller , and are indented at their bafe , where is f iliated 
a fcaly ntciarium to each petal , which is thick and in- 
curved, inclining to the border , to which the fiyle is fixed % 
it hath many ftamina , which are briftiy , the length 
of the petals , terminated by roundifh fummits. In the 
center is fituated the roundijh germen , which is lengthened 
to a column , fupporting a fender fiyle , crowned by a four- 
cornered obtufe ftigma. The germen afterward becomes 
four-cornered berry with four cells , each inclofing one glo- 
bular feed. 
This genus of plants is ranged in the feventh fe&ion 
of Linnaeus’s twentieth clafs, which includes thofe 
plants whole flowers have many ftamina joined to the 
ftyle, forming a column of one body. 
The Species are, 
1. Grewia [Occident alis) foliis fubovatis crenatis. Grewia 
with oval crenated leaves. Ulmi facie arbufcula, fEthi- 
opica, ramulis alatis, floribus purpurafcentibus. Hort, 
Amft. i.p. 165. tab. 85. Ethiopian Shrub with the ap- 
pearance of Elm , winged branches , and purplifh flowers. 
2. Grewia ( Africanus ) foliis ovato-lanceolatis ferratis. 
Grewia with oval fpear-fhaped leaves which are flawed. 
The firft fort has been long preferved in many curious 
gardens, both in England and Holland, and is fi- 
gured by Dr. Plukenet, by the title of Ulmifolia ar- 
bor Africana baccifera, floribus purpureis; but by 
Dr. Boerhaave it was fuppofed to be one of Father 
Plumier’s American plants, intitled Guidonia Ulmi 
foliis, flore rofeo ; but the charaders of this do not at 
all agree with thofe of the Guidonia, that particular 
fpecies of this genus being in the royal garden at Paris, 
which is extremely different from this. It grows na- 
turally at the Cape of Good Hope, from whence I 
have received the feeds, which have fucceeded in the 
Chelfea garden. 
This will grow to the height of ten or twelve feet, 
and has a ftem and branches very like thofe of the 
fm all-leaved Elm, the bark being fmooth, and of the 
fame colour as that of Elm when young ; the leaves 
are alfo very like thofe of the Elm, and fall off in 
winter ; the flowers are produced fingly along the 
young branches from the wings of the leaves, which 
are of a bright purple colour ; thefe appear toward 
the end of July, and continue in Auguft, and the be- 
ginning of September, but are never fucceeded by 
fruit in this country. 
This may be propagated from cuttings or layers ; the 
cuttings fliould be taken off, and planted in April, 
before the buds fwell, for they do not fucceed 
well after; thefe cuttings fhould be planted in 
fmall pots filled with loamy earth, and the pots fliould 
be plunged into a moderate hot-bed of tanners bark, 
where, if they are duly watered, and in the heat of 
the day Ihaded from the fun, they will take good root 
in about two months, and may then be gradually in- 
ured to bear the open air, into which they fliould be 
removed in June, and placed in a flickered fituation, 
where they may remain till autumn, when they muft 
be removed into the green-houfe ; the beft time to lay 
down the layers of this plant is in the fpring, before 
the buds come out, and thefe will be rooted by the 
fame time the following year, when they may be cut 
off from the old plants, and planted each into a fe- 
parate pot filled with a foft loamy foil. 
The beft time to remove or tranfplant this plant is, 
either in the fpring, juft before the buds begin to 
fwell, or in autumn, when the leaves begin to drop % 
for in fummer, when the plants are in full leaf, it will 
be very improper to difturb them. 
In winter thefe plants fhould be placed in the green- 
houfe, for they are too tehder to live abroad in Eng- 
land ; but they fhould have as much free air as poffible 
in mild weather, for they only require to be protected 
from froft, and after their leaves are fallen, they will 
require very moderate watering ; but in fummer they 
fliould be conftantly watered three or four times a week 
in dry weather, and placed in a flickered fituation, 
with other hardy green-houfe plants, where they will 
add to the variety. 
The feeds of the fecond fort were lent me by Monf. 
Richard, gardener to the King of France at Mar- 
fellies. 
