Ha heptaphyllos baccifera. C. B. P. 322. Seven-leaved 
bulb-bearing wsothwort. 
3 - Dentaria [Enneaphyllos) foliis ternis ternatis. Lin. 
Sp. Plant. 653. Toothwort with three-leaved trifoliate 
leaves. Dentaria triphyllos. C. B. P. 322. Three-leaved 
T oothwort. 
The firft fort rifes with a ftrong Balk afoot and a half 
high, garnifhed with a leaf at each joint, compofed 
of five lobes, which are four inches long, and near 
two broad in the wicleff part, ending in acute points, 
deeply fawed on their edges ; thefe are fmooth, and 
Band on long foot-ftalks •, the flowers grow in loofe 
fpikes at the top of the flalks ; they are fmall, of a 
blufli colour, and fucceeded by long taper pods filled 
with fmall roundifh feeds. It grows in the Brady 
woods in the fouth of France and Italy. 
The fecond fort rifes with (lender Balks about a foot 
high; the leaves at the bottom have feven lobes, 
thofe a little above five, others but three, and at the 
upper part of the ftalk they are fingle : the flowers 
grow in cluders at the top of the Balk ; thefe have 
four obtufe purple petals, and are fucceeded by taper 
pods filled with roundifh feeds. 
The third fort rifes with an upright Balk a foot high ; 
the leaves are compofed of nine lobes, three growing 
together, fo that one leaf has three times three ; the 
flowers grow in fmall bunches on the top of the Balks, 
and are fucceeded by fmall taper pods filled with 
roundifh feeds. 
Thefe plants grow on the mountains in Italy, and in 
the woods of AuBria. The fecond fort is found wild 
in fome parts of England, but particularly near Hare- 
field, in moifi fhady woods, and is feldom preferved 
in gardens : this produces bulbs on the fide of the 
Balks, where the leaves are fet on, which, if planted, 
will grow and produce plants. Thefe plants are pro- 
pagated by feeds, or parting their roots ; the feeds 
fhould be lown in autumn, foon after they are ripe, 
in a light fandy foil and a fhady fituation : in the 
Ipring the plants may be taken up where they grow 
too clofe, and tranfplanted out in the like foil and fi- 
tuation ; where, after they have taken root, they 
will require no farther care, but to keep them clear 
Trom weeds: the fecond year they will produce flowers, 
and fometimes perfect: their feeds. 
The befi time to tranfplant the roots is in October, 
when they fhould be planted in a moifi foil and a 
Brady fituation ; for they will trot live in a dry foil, or 
when they are expofed to the fun. 
DEW is by fome defined to be a meteor bred of a 
thin cold vapour, or compofed of the Beams and 
vapours of the earth ; which, being exhaled by the 
heat of the fun, and kept fufpended during his pre- 
fence, do, upon his abfence, convene into drops, and 
then fall down unto the earth again. 
Others define it, a thin, light, infenfible mifi or rain, 
falling while the fun is below the horizon. 
The origin and matter of dews are, without doubt, 
from vapour and exhalations of the earth and water, 
raifed by the warmth of the fun and earth, &c. 
There being many vapours in the air, though not 
always vifible, hence it comes to pafs, that even in 
clear weather great dews fall, efpecially in countries 
where it feldom rains ; for when it happens that the 
fcattered vapours are colledted and condenfed together, 
and forced downwards, they mufi needs fall, and be- 
dew the plants and grafs. 
The thin veficles, of which vapours confiB, being 
once detached from their bodies, keep rifing in the 
air till they arrive at fuch a fiage as is of the fame 
Specific gravity with themfelves, when their rife is 
Bopped : now, as it is the warmth or fire that dilates 
the parts of water, and forms thofe veficles that are 
fpecifically lighter than the air, and are capable of af- 
cending therein.; fo when that heat declines, or is 
loB, as by the approach or contiguity of any colder 
body, the veficles condenfe, and become heavier and 
defcend. 
Therefore the fun warming the atmofphere in the 
day-time, by the continual influx of his rays, the va~ 
3 
podrs being dnce raifed, continue their progrefs, not 
meeting with any thing to increafe their gravity, 
till luch time as they are got far beyond the reach of' 
the refleded warmth of the earth in the middle re- 
gion of the atmofphere, and there condenfe and form 
clouds. 
Though fome fay, it is difputable whether dews ever 
congregate fo as to form clouds, as they are only 
elevated by the fun ; fo that when that power is gone, 
as it is after the letting of the fun, they immediately 
defcend ; and this is more obfervable in very warm 
weather, and very hot climates. 
The time for the falling of the dew is either before 
fun-rifmg, or after lun-let ; that it may regularly fall 
at fuch times, it is necefiary for the air to be calm, 
for windy or Bormy weather hinders it ; but when it 
is calm weather, and gentle breezes are felt from the 
wefi about the letting, and from the eafi about the 
rifing of the fun, it is probable, that by moderately 
cooling the air, they colled the vapours and precipi- 
tate them ; and becaufe the morning breezes are more 
general than the evening ones, for this reafon the 
evening dews fall only here, and there, but thofe in 
the morning feldom fail to be univerfal : or, as it 
may be otherwife expreffed, when the fun is got be- 
low the horizon, the atmofphere cools the vapours, 
which have in the preceding day been raifed by the 
warmth- of the earth; and the rays of the fun being 
lodged there, as foon as they are got out of the air, 
they begin to condenfe apace, and lpend their Bock 
of heat and fire on the cold moifi air that they pafs 
through. 
Hence it is, that dews are more copious in the fpring 
than other feafons, there being a greater Bock of va- 
pour in readinefs, by reafon there has been but a fmall 
expence thereof during the winter’s cold and frolt 
than at other times. 
It is found by experience, that the dews are more 
copious in hotter countries than in cold, as Pliny ob- 
ferves of the fummer nights in Africa, which he calls 
Rofcidte asfiate nodes ; the reafon of which feems 
to be this, that in the day-time the heat of the fun 
raifes abundance of vapours out of the water ; which 
vapours are fo extremely rarefied by the fame heat, 
that they are difperfecl far and wide ; but the cool of 
the night brings them together, and condenfes them 
to that degree, that they fall to the ground, but not 
in fuch large drops as rain does ; but in colder coun- 
tries, where there are frequent rains, and the vapours 
are lefs rarefied, mofi of them come down in rain, 
and but a fmall part turns to dew : befides, in Africa 
there is a great difference between the heat of the day 
and night, particularly in fummer ; for their nights 
are long, and very cold ; whereas in northern coun- 
tries they are little colder than the day, and much 
flhorter than in places nearer the line. 
Pliny likewife relates of Egypt, that it abounds in 
dews throughout all the heat of fummer ; for the air 
being there too hot to conffipate the vapours in the 
day-time, they never gather into clouds, and for that 
reafon they have no rain. But it is known, in climates 
where the days are exceffive hot, the nights are re- 
markably cold, fo that the vapours that are raifed 
after fun-fet are readily condenfed into dews : or, 
perhaps notable coldnefs may be rather the effedt than 
the caufe of the quantity of dews ; for much vapour 
being raifed by the great heat of the earth, and the 
Bock of fire being lpent on it in the day-time, the 
influx of fuch a great quantity of moifiure mufi greatly 
chill the air. 
The difference between dew and rain feems to be 
only this, that dew fails at fome particular times as 
aforefaid, and in very fmall drops, fo as to be feen 
when down, but fcarce perceivable while it is falling ; 
whereas rain falls at any time, and in groffer drops. 
The reverend Dr. Hales, in his Treatife of Vegetable 
Statics, tells us, That in order to find out the quan- 
tity of dew that fell in the night on the 15th of Au- 
guff, 7 p. rn. he took two glazed earthen pans, which 
were three inches deep, and twelve indies diameter 
in 
