T A N 
fert the fhorteft and plained; method of making and 
managing thefe hot-beds, as they are practifed by the 
in oft knowing perfons, who have long made ufe of 
thefe hot-beds •, and firft, I fliall begin with the 
choice of the Tan. 
The tanners in fome parts of England do not grind 
the Bark to reduce it into fmall pieces, as is commonly 
praftifed by the tanners near London, where there is 
great difference in the fize of the bark, fome being 
ground much fmaller than the other, according to the 
different purpofes for which it is intended ; but in 
many places the Bark is only chopped into large 
pieces, which renders it very different for the ufe of 
hot-beds ; for if the Tan is very coarfe, it will require 
a longer time to ferment than the fmall Tan ; but 
when it begins to heat, it will acquire a much greater 
degree, and will retain the heat a much longer time 
than the fmall ; therefore where there is choice, the 
middling-lized Tan Ihould be preferred, for it is very 
difficult°to manage a hot-bed when made of the 
large ft Tan •, the heat of which is often fo great, as 
to fcald the roots of plants, if the pots are fully 
plunged into the bed ; and 1 have known this violent 
heat continue upward of two months, fo that it has 
been unfafe to plunge the pots more than half their 
depth into the Tan, till near three months after the 
beds have been made •, therefore where the perfons, 
who have the care of thefe beds, do not diligently ob- 
ferve their working, they may in a fhort time deftroy 
the plants which are placed in the beds : on the other 
hand, if the Tan is very fmall, it will not retain the 
heat above a month or fix weeks, and will be rotten 
and unfit for a hot-bed in a fhort time ; fo that where 
the middle-fized Tan can be procured, it fhould al- 
ways be preferred to any other. 
The Tan fhould be always fuch as been newly taken 
out of the pits, for if it lies long in the tanners 
yard before it is ufed, the beds feldom acquire a pro- 
per degree of heat, nor do they continue their heat 
long ; fo that when it has been more than a fortnight 
or three weeks out of the pit, it is not fo good for 
ufe as that which Is new. If the Tan is very wet, it 
will be proper to fpread it abroad for two or three 
days, to drain out the moifture, efpecially if it is in 
autumn or winter feafon, becaufe then, as there will 
be little fun to draw a warmth into the Tan, the 
moifture will prevent the fermentation, and the beds 
will remain cold ; but in the fummer feafon, there is no 
great danger from the moifture of the Tan. The heat 
of the fun through the glaffes will be then fo great, as 
foon to caufe a fermentation in the Tan. 
Thefe Tan-beds fhould be always made in pits having 
brick-walls round them, and a brick pavement at the 
bottom, to prevent the earth from mixing with the 
Tan, which will prevent the Tan from heating. Thefe 
pits muft not be lefs than three feet deep, and fix feet 
in width, but feven is better ; the length muft be in 
proportion to the number of plants they are to contain, 
but if they are not ten feet in length, they will not 
retain their heat long*, for w f here there is not a good 
body of Tan, the outfide of the bed will foon lofe 
its heat, fo that the plants which are there plunged, 
will have no benefit of the warmth, nor will the mid- 
dle of thefe beds retain their heat long, fo that they 
will not anfwer the purpofe for which they are in- 
tended. 
When the Tan is put into the bed, it muft not be 
beaten or trodden down too clofe, for that will caufe 
it to adhere, and form one folid lump, fo that it will 
not acquire a proper heat *, nor fhould it be trodden 
down at the time when the pots are plunged into the 
beds, to avoid which there fhould be a board laid 
crofs the bed, which fhould be fupported at each end, 
to prevent its refting upon the Tan, upon which the 
perfon fhould ftand who plunges the pots, fo that the 
Tan will not be preffed down too clofe. When the 
Tan is quite frefh, and has not been out of the pits 
long enough to acquire a heat, the beds will require a 
fortnight, or fometimes three weeks, before they will 
be of a proper temperature of warmth to receive the 
TAR 
plants; but in order to judge of this, there fliouM 
be three or four flicks thruft down into the Tan, 
about eighteen inches deep, in different parts of the 
bed, fo that by drawing out the flicks, and feeling 
them at different depths, it will be eafy to judge of 
the temper of the bed ; and it will be proper to let 
a few of thefe flicks remain in the bed after the plants 
are plunged, in order to know the warmth of the 
Tan, which may be better judged of by feeling thefe 
flicks, than by drawing out the pots, or plunging the 
hand into the Tan. 
When the Tan is good, one of thefe beds will retail! 
a proper degree of heat for near three months ; and 
when the heat declines, if the Tan is forked up and 
turned over, and fome new Tan added to it, the heat 
will renew again, and will continue two months longer; 
‘ fo that by turning over the Tan, and adding fome new 
Tan every three months or thereabouts, as the bed is 
found to decline of its heat; they may be continued 
one year, but every autumn it will be proper to take 
out a good quantity of the old Tan, and to add as 
much new to the bed, that the heat of the bed may 
be kept up in winter; for if the heat is fuffered to de- 
cline too much during the cold feafon, the plants will 
fuffer greatly ; to prevent this, there fhould always' 
be fome new Tan added to the bed in winter, when 
the heat is found to decline ; but the Tan fhould be 
laid in a dry place a week or ten days to dry, before 
it is put into the bed, otherwife the moifture will chill 
the old Tan in the bed, and prevent the fermentation ; 
fo that unlefs the Tan is turned over again, there will 
be little or no heat in the beds, which often proves 
fatal to the plants which are plunged in them ; there- 
fore whoever has the management of thefe beds,' 
fhould be very careful toobferve conftantly the warmth 
of the Tan, fince, upon keeping the beds in a due 
temperature of warmth, their whole fuccefs depends ; 
and where this caution is not taken, it frequently hap- 
pens that the Ananas plants run into fruit very finally 
or the plants are infeded by infeds, both which are 
occafioned by the growth of the plants being flopped 
by the decline of the heat of the Tan 5 therefore great 
regard muft be had to that, efpecially in winter. 
The great advantages which thefe tan-beds have of 
thofe which are made of horfe-dung, are the mode- 
rate degree of heat which they acquire, for their heat 
is never fo violent as that of horfe-dung, and they 
continue this heat much longer ; and when the heat 
declines, it may be renewed, by turning the beds 
over, and mixing fome new Tan with the old, which 
cannot be fo well done with horfe-dung • and like- 
wife the beds will not produce fo great fteams, which 
are often injurious to tender plants, fo that thefe Tan- 
beds are much preferable to thofe of horfe-dung for 
moft purpofes. 
Tan, when it is well rotted, is alfo an excellent ma- 
nure for all cold and ftiff lands ; and if it is laid upon 
Grafs ground in autumn, that the rains in winter 
may walh it into the ground, it will greatly improve 
the Grafs ; but when it is ufed new, or in the fpring 
of the year, when dry weather comes foon after, it 
is apt to caufe the Grafs to burn, which has occa- 
fioned the difufe of Tan in many places ; but if pro- 
perly ufed, it will be found an excellent dreflina; for 
all ftiff lands. 
T APIA. See Crateva. 
TARCHONANTHUSi Lin. (Sen. Plant. 846, 
The Characters are, 
It has a flower compofed of fever al hermaphrodite florets , 
included in one common top-Jhaped empalemeni , which is 
jhort , permanent , and hairy . The florets are uniform 4 
fannel-Jhaped , and of one petal , indented in five parts at 
the top\ they have each five very Jhort hair -like ftamina\ 
terminated by cylindrical tubulous fummits longer than the 
petal , and an oblong gerinen , fupporting a fiyle the length 
of the ft amina, cfozmed by two awl-Jhafed ftigmas which 
open lengthways. The germen afterward turns to a Jingle 
oblong feed, crowned with down , which ripens in the em- 
palement . 
n B This 
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