DRY 
nel or seed. The definition just given, will 
apply to every seed-vessel denominated 
driipa in the “ genera plantarum.” The 
mond is a drupa, so is the seed-vessel of 
the elm-tree and the genus rumphia ; though 
tin- from being pulpy or succulent, the first 
and third are of a substance like leather ; 
the second like parchment. The same may 
be said of the walnut, pistacia-nut, and 
some others. Again, the seeds of the elm, 
flagellaria, and the mango-tree, are not con- 
tained in a stone. The seed-vessel of buiT- 
reed is dry, shaped like a top, and contains 
two angular stones. This species of fruit, 
or more properly seed-vessel, is commonly 
roundish, and when seated below the calyx, 
or receptacle of the flower, is furnished, like 
the apple, at the end opposite to the foot- 
stalk, with a small umbilicus or cavity, pro- 
duced by the swelling of the fruit before 
the falling off of the fiower-cup. 
dry rot, a disease incident to timber 
used for building, such as flooring-boards, 
joists, wainscoting, &c. Dr. Darwin is of 
opinion, that the dry-rot may be entirely 
prevented, by soaking the timber first in 
lime-water, till it has absorbed as much of 
it as possible, and, after it has become diy, 
immersing it in a weak solution of vitriolic 
acid in water, which he supposes will not 
only preserve it from decay for many cen- 
turies (if it be kept dry), but also render it 
less inflammable; a circumstance that 
merits considerable attention in constructing 
houses. In the Transactions of the Society 
for the Encouragement of Arts, we meet 
with the following account of the cause of 
the dry rot in timber, and the method of 
preventing it, communicated by Mr. Batson, 
of Limehouse. He observes, that the dry 
rot having taken place in one of his parlours, 
to such a degree as to require the pulling 
down part of the wainscot every third year, 
and perceiving that it arose from a damp, 
stagnated air, and from the moisture of the 
earth, he determined, in the month of June, 
1783, to build a narrow closet next the wall 
through which the moisture came to the 
parlour. This expedient had the desired 
effect. But, though the rot in the parlour 
was totally stopped, the evil soon appeared 
in the closet, where fungi of a yellow colour 
arose in various parts. In the autumn of 
the year 1786 the closet was locked up 
about ten w'eeks : on opening it, numerous 
excrescences were observed about the lower 
part ; a white mould was spread by a plant 
resembling a vine, or sea-weed ; and the 
whole of the inside, china, &c. was covered 
DRY 
with a fine powder of the colour of brick- 
dust. On cleaning out the closet; it was 
discovered that the disease had affected the 
wood so far as to extend through every 
shelf, and the brackets that supported them. 
In the beginning of the year 1780, he de- 
termined to strip the whole closet of lining 
and floor, not to leave a particle of the 
wood behind, and also to dig, and take 
away, about two feet of the earth in depth, 
and leave the walls to dry, so as to destroy 
the roots or seeds of the evil. When, by 
time, the admission of air, and good brush- 
ing, it had become properly dry and cleans- 
ed, he filled it, of sufficient height for the 
joists, with anchor-smith’s ashes, because 
no vegetable will grow in them. The joists 
being sawed off to their proper lengths, and 
fully prepared, they and their plates were 
well charred, and laid upon the ashes ; par- 
ticular directions being given, that no 
scantling or board might be cut or planed 
in the place, lest any dust or shavings might 
drop among the ashes. The flooring- 
boards being very dry, he caused them to 
be laid close, to prevent the dust getting 
down, which perhaps, in the course of time, 
might bring on vegetation. The framing of 
the closet was then fixed up, having all the 
lower pannels let in, to be fastened with 
buttons only, so that, if any vegetation 
should arise, the pannels might witti ease be 
taken out and examined. In some situa- 
tions it might be expedient and necessary 
to take out a greater depth of earth ; and 
where ashes can be had from a foundry, 
they may be substituted for those of anchor- 
smiths ; but house ashes are by no means 
to be depended upon. At the expiration of 
seven years from the period of making this 
experiment the wainscot was removed, and 
the flooring-boards also taken up, when they 
were found entirely free from any appearance 
of the rot : two pieces of wood (yellow fir) 
which had been driven into the wall as 
plugs, without being previously charred, 
were alone affected with this disease. 
DRYANDRIA, in botany, so named in 
honour of Jonas Dryander, a Swede, and a 
most excellent botanist, a genus of the 
Dioecia Monadelphia class and order. Na- 
tural order of Tricoccae. Euphorbiae, Jus- 
sieu. Essential character: calyx two-leaved ; 
corolla five-petalliid ; or, calyx five-leaved, 
resembling a corolla, surrounded by a two 
or three leaved calycle ; stamina nine ; fruit 
three or four grained. There is but one 
species, viz. D. cordata. 
DRYAS, in botany, a genus of the 
