T H L 
T H L 
receive all their nourifhment merely by imbibing the 
next adjoining moifture with the earth ; and confe- 
quently the (hell of the earth, next the furface of the 
roots, would always be confiderably drier, the nearer 
it is to the root, which I have not obferved to be fo. 
And by experiments *8 and 19, the roots would be 
very hard put to it to imbibe fufftcient moifture in dry 
fummer weather, if it were not thus conveyed to 
them by the penetrating warmth of the fun ; whence 
by the fame genial heat, in conjunbtion with the at- 
trablion of the capillary fap-veftels, it is carried up 
through the bodies and branches of vegetables *, and 
thence palling into the leaves, it is there moft vigo- 
roufly added upon in thole thin plates, and put into an 
undulating motion by the fun’s warmth, whereby it 
is moft plentifully thrown off, and perfpired through 
their furface ^ whence, as foon as it is difentangled, it 
mounts with great rapidity in the free air. 
But when, towards the latter end of Odlober, the vi- 
gour of the fun’s influence is fo much abated, that 
the firft thermometer was fallen to three degrees above 
the freezing point, the fecond to ten degrees, the fifth 
to fourteen degrees, and the fixth to fixteen degrees ; 
then the bride undulations of the moifture of the 
earth, and alfo of the afeending fap, much abating, 
the leaves faded and fell off. 
The greateft degree of cold in the following winter, 
was in the firft twelve days of November, during 
which time, the fpirit in the firft thermometer was 
fallen four degrees below the freezing point, the 
deepeft thermometer ten degrees •, the ice on ponds 
was an inch thick-, the fun’s greateft warmth at the 
winter l'olftice, in a very ferene, calm, frofty day, 
was, againft a fouth afpedl of a wall, 19 degrees, and 
in a free open air, but 11 degrees above the freezing 
point. 
From the 10th of January to the 29th of March was 
a very dry feafon, when the green Wheat was gene- 
rally the fineft that was ever remembered : but from 
the 29th of March, 1725, to the 29th of September 
following, it rained more or lefs every day, except 
ten or twelve days about the beginning of July and 
that whole feafon continued fo very cool, that the fpi- 
rit in the firft thermometer rofe but to 24 degrees, ex- 
cept now and then a fhort interval of fun-fhine ; the 
fecond only to 20 degrees, the fifth and fixth to 24 
and 23 degrees, with very little variation fo that, 
during this whole fummer, thofe parts of roots which 
were two feet under ground, had three or four degrees 
more warmth than thofe which were but two inches 
under ground -, and at a medium, the general degree 
of heat through this whole fummer, both above and 
under ground, was not greater than the middle of the 
preceding September. 
T FI LAS ft I. Tourn. Inft. R. H. 2 12. tab. 10 1. Lin. 
Gen. Plant. 719. [0 a«Wi, fo called of tocom- 
prefs or fqueeze together, becaufe the feed-veffels of 
it are very much compreffed.] Mithridate, or Treacle 
Muftard. 
The Characters are. 
The empalement of the flower is compofed of four oval con- 
cave petals which fall off. The flower has four oval petals 
double the flze of the empalement, placed inform of a crofs -, 
it has fix flamina half the length of the petals , two of 
which are fhorter than the others , terminated by acute 
fummiis, and a roundifh compreffed germen fupporting a 
Jingle ftyle the length of the flamina , crowned by an obtufie 
ftigma. The germen afterward becomes an oval, heart- 
Jhaped, compreffed Utile pod, with an acute border divided 
into two cells by an intermediate partition , containing two 
or three feeds in each. 
This genus of plants is ranged in the firft feftion of 
Linnaeus’s fifteenth clafs, which contains thofe plants 
whofe flowers have four long and two fhorter ftamina, 
and the feeds are included in fhort pods. 
The Species are, 
1. Thlaspi {Camp eft re) filiculis fubrotundis, foliis fa- 
gittatis dentatis incanis. Hort. Cliff. 330. Treacle 
Muftard with roundifh pods , and arrow-pointed, hairy , 
and indented leaves. Thlafpi arvenfe, vaccarias incano 
I folio niajus. C. B.P. 106. Mithridate Muftard, or Baft 
l tard Crefs. 
2. Thlaspi ( Arvenfe ) filiculis orbicularis, foliis oblon- 
gis dentatis glabris. Flor. Lapp. 251. Treacle Muftard 
with orbicular pods, and oblong , indented, fimooth leaves . 
Thlafpi arvenfe filiquis latis. C. B. P. 105. Treacle 
Muftard, or Penny Crefs. 
3. Thlaspi {Perfoliatum) filiculis obcordatis, foliis cau- 
linis cordatis glabris fubdentatis, petalis longitudi- 
ne calycis, caule ramofo, Lin. Sp. Plant. 902. Treacle 
Muftard with heart-Jhaped , fimooth, indented leaves , the 
petals 'of the flower as long as the empalement, and a 
branching ftalk. Thlafpi arvenfe, perfoliatum majus. 
C. B. P. 106. The greater , wild , perfoliate Treacle 
Muftard. 
4. Thlaspi (. Alpeftre ) filiculis obcordatis, foliis fubden- 
tatis, caulinis amplexicaulibus, petalis longitudine 
calycis, caule fimplici. Lin. Sp. Plant. 903. Treacle 
Muftard with heart-Jhaped leaves embracing the fttalks, 
the petals of the flower as long as the empalement, and a 
Jingle ftalk. Thlafpi perfoliatum minus. C. B. P. 106. 
The leaft perfoliate Treacle Muftard . 
5. Thlaspi {Peregrinum ) filiculis fuborbiculatis, foliis 
lanceolatis integerrimis. Lin. Sp. Plant. 903. Treacle 
Muftard with orbicular pods , and fpear-Jhaped entire 
leaves. Thlafpi capfulis cordatis peregrinum. Bocc. 
Hift. 2. 927. Foreign Treacle Muftard with heart-Jhap- 
ed pods. 
6. Thlaspi ( Alliaceum ) filiculis fubovatis ventricofis, fo- 
liis oblongis obtufis dentatis glabris. Prod. Leyd. 334. 
Treacle Muftard with almoft oval f welling pods, and ob- 
long, blunt , fmooth, indented leaves. Thlafpi Allium 
redoiens. Mor. Hi ft. 2. p. 297. Treacle Muftard with 
the fmell of Gar lick. 
7. Thlaspi ( Hirtum ) filiculis fubrotundis pilofis, foliis 
caulinis fagittatis hirfutis. Prod. Leyd. 333. Treacle 
Muftard with roundifh hairy pods , and hairy arrow- 
pointed leaves on the ftalks. Thlafpi villofum capfulis 
hirfutis. C. B. P. 106. Perennial Mithridate Muftard. 
8. Thlaspi ( Montanum ) filiculis obcordatis, foliis gla- 
bris radicalibus carnofis obovatis integerrimis, cauli- 
nis amplexicaulibus corollis calyce majoribus. Lin. 
Sp. Plant. 902. Treacle Muftard with heart-Jhaped pods, 
the lower leaves fmooth and entire , and the upper em- 
bracing the ftalks. Thlafpi foliis globul arias. J. B. 2. 
p. 926. Treacle Muftard with a blue Daifiy leaf. 
The firft fort grows naturally amongft the Corn in 
divers parts of England, as alfo on the fide of dry 
banks -, it is a biennial plant, which perifhes foon af- 
ter it has ripened its feeds. The root is compofed of 
ligneous fibres which fpread in the ground ; the 
leaves are near three inches long, narrow at their bafe, 
and broader toward their points, where they have fe- 
veral indentures ; they are hoary on both fides. The 
ftalk rifes about a foot high, branching out toward 
the top, and is pretty clofely garnifhed with leaves 
placed alternately, fitting dole to the ftalks, whofe 
ears embrace the ftalk. The flowers are produced in 
fhort fpikes at the end of the ftalks ; they are final!, 
white, and compofed of four petals placed in form 
of a crofs ^ thefe appear in June, and are fucceeded 
by roundifh capfules having two cells, containing two 
or three feeds in each, which ripen in Auguft. The 
whole plant has a warm biting tafte. The feeds of 
this are frequently ufed inftead of thofe of the next, 
which is the fort direded to enter the compofition of 
Venice treacle. 
The fecond fort is an annual plant, which grows na- 
turally in feveral parts of England : I have found it 
growing in plenty in the meadows on the right hand 
fide of Godaiming. The root of this is compofed 
of {lender fibres ; the ftalk rifes a foot high, is an- 
gular, channelled, and fmooth ; the leaves are about 
two inches long, are fmooth and indented, of a deep 
green colour, and fit clofe to the ftalks ; the flowers 
are produced in loofe fpikes toward the upper part of 
the ftalks ^ they are final), white, and compofed of 
four petals placed croffwife like the former ; thefe 
are fucceeded by broad, flat, roundifh, compreffed 
pods, having leafy borders which have two cells, 
each 
