FRU
gular proportion of length, in regard to one another. To thefe he next fubjoins two clafles of' fuch of them as have ever two of their Jiamtna iliorter than the reft. The finr of thefe (the fourteenth clafs of the general order) is of the didynamia : the word derived from the before-men- . tioned <Tij and fvmftis, power or efficacy, fignifies with him fuch flowers as have two of their male parts of more effica- cy than the reft ; and in this dais he accordingly compre- hends all thofe plants which have hermaphrodite flowers, two of whofe Jfanuna are longer, and of greater efficacy in the great work of fecundating the feeds, than the reft : of this clafs are the- thyme, lavender-, bajil 7 &e.
The fecond of thefe (the fifteenth clafs in the general order) is of the tetradynamia : the word derived from the before-men- tioned TElpojj and dwjolfAii, fignifies a flower with four of its male parts of more efficacy than the reft ; and in this clafs he comprehends the plant 1 ; with hermaphrodite flowers, four of the Jlamina of which are longer than the reft ; of this clafs are the femuy-grafs, radijh, mt/f'ard, &-c.
From thefe he proceeds to thofe hermaphrodite flowers whofe Jlamina cohere, either mutually among one another, in differ- ent manners ; or with the [if/; Hum -of the flower : thefe co alitions of the jiamina he calls brotherhood;., or communities, and according to the different ftate ot thefe", and their con- junctions with the pijlillum, he eftablifhes five clafles of them. The firft of thefe (the fifteenth in the general order) is of the monadelfhia : the word derived from the before-mentioned fjnove'i, Jingle, and dfcktyz., brotherhoods, or communities, Iignifies with him a flower whole ifiqmmUi by means of the filaments running id among one another, are all formed into one body-^ and under this clafs he comprehends thofe plants with hermaphrodite flowers, whofe jiamina, or male parts, are all bound together in one body : of this clafs arc the crane' s-
■ hill, mallow, &c.
The fecond of thefe (the feventeenth clafs in the general or- der) is of the diadelphia : the word derived from the before- mentioned a); and d$s\(pu$ fignifies with him a flower whofe Jiamina are, by the conjunction of their filaments, formed in- to two bodies ; and under this clafs he comprehends thofe plants which have' hermaphrodite flowers, the Jlamin* of which are fo cluftcred' together into two bodies : of this are thefu-
■ mitory, milkwort, broom, &c.
The third of thefe (the eighteenth in the general order-) is of , the polyadelphia : the word derived from the before-mention- ed isoXvq and d'JsXpa, fignifies with him a flower whofe male parts are ciuftered into three or more feparate bodies ; and in this he comprehends thofe plants with hermaphrodite flowers, whofe Jlamina, by the conjunction of their filaments, are formed into three or more clutters : of this clafs are the orange, St. "John's wort, &c.
The fourth of thefe clafles (the nineteenth in the general or- der) is of the fyngencfia : the word derived from <ruv, together, and yfaetritf generation, origin, or formation, fignifies with him fuch flowers as have their male parts naturally formed into a Angle regular congeries ; and accordingly he compre- hends under this clafs fuch plants as have hennaphrodite flowers, .the Jiamina of which, by the junction of their apices, are form- ed into a Angle, regular, cyliudric body : of this clafs are the lettuce, fucccry, hawkweed, life.
The fifth of thefe clafles (the twentieth in the general order) is of the gynandria : the word derived from ymri, a woman, or fe- male, andamip, male, fignifies with this author a conjunction of the male and female parts of a flower at their origin ; and he accordingly comprehends under this clafs thofe plants which have hermaphrodite flowers, the Jlarnina, or male parts of which grow to the pijlillum, or female part of the flower, and not to the receptacle of the feeds : of this clafs are the barrenwort, pajjion-fiower-, birtbivort, &c. Next after thefe he ranges thofe plants which have flowers not hermaphrodite, but regularly and diftinctly male and fe- male, as the fexes in animals are difpofed ; and after thefe fuch plants as have flowers irregularly of one, or the other, or foxrietirhfis of both fexes : Of thefe he eltablifhcs only three claffes. The firft of thefe (the twenty-ntft clafs in the general order) is of the monoecia : the word derived from the before-mention- ed y.6uec 7 and olxog, a habitation, fignifi.es with this author fuch .plants as have their diftinct flowers on the fame indi- vidual ; and he comprehends aocordingly under it thofe plants which have the male and female floweis diftinct in them- felvcs, but placed on the fame plant, or the different ftalks from the fame root : of this clafs arc the aider, midberry, ama- ranth, arrowhead, C3V.
The fecond of thefe (the twenty-fecond clafs in the general order) is of the dioecia : the word derived from the fame oi'ko? and S\q, fignifies with him plants which have their male and female flowers, not on the fame individual , and accordingly comprehends under it fuch plants as have diftinct male and fe- male flowers, on different plants of the fame (pedes, either of which, the male and female plants, as they are hence called, might nave arifen from the fame feed : of this clafs are the willow, mijletoe, hemp, zn<\.fpinach, isc. The third of thefe (the twenty-third in the general method) is of the polygamia : the word derived from sreXuff, many, and . Append.
F R
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frxpoi, marriage, fignifies with this authorplants which have a diverfity ot combinations and many ways of frucTification, ' m the fame fpecies ; and accordingly hs comprehends under this clafs thole plants which have, in the fame fpecies, fome flowers male, others female, each diftinfl and perfect in its kind; and others mixed or hermaphrodite, witl thi male and female organs of fructification both in eacl: : < - ; .is clafs are pellitary of the ivall, orraebe, the ajh, He. After all thefe he places thofe plants whofe flowers are ei- ther absolutely invifible, or fcarce difcernible by the eye : of thele he makes only one, his twenty fourth and lad clafs, the ciyptogamia : the word derived from xpWloV, hidden, or con- cealed, and the before-mentioned yoipoi, or marriage, fig- nifies a fet of plants, in which the fructification is concealed : and under this laft clafs he comprehends thofe plants which either flower, as is generally fuppofed, within the fruit, or have the organs of their fructification fo mingled as to efcape our obfervation: of this clafs are the fens, mojjes, liverworts, and mujfjroomt.
Thefe are the claffes into which this author has regularly and certainly reduced the whole vegetable world • the cha- racters of which are fo expreinve, and the parts they are founded upon (o fixed and invariable in their nature and of- fice, that there feems no reafon hereafter to perplex the world with any new fyftem.
As the claffes are here all taken from the number, lite rnd dif- pofitionof the male parts of the flower; fo the oni rs vhich make their fubdiitinctions are, by this author, deduced from the differences of the female parts ox pijtillum ; and as that is fingle, double, triple, and fo on, they are on the lame prin- ciples named monogynia, digynia, trigynla, £jf>; It were to be wifhed indeed that the characters of the dif- ferent genera of thefe claffes were as perfect and accurate as the claffes themfelves : this, however was more than the work of one man; the author- has fixed the general diffinc- tion, and led the way ; and it is eafy now for a much lefs genius to follow him.
FROWEY, a term ufed by workmen for timber which is evenly tempered all the way, and works freely without tearing. Build Diet, in voc.
FRXJlT(Suppl.)~Ripeni„ g of Fruit. For the method of for- warding this operation of nature, fee the article Ripening Append. '
FRUSH, or Frog, among farriers, that part of a horfe's foot, which is placed from the middle of the fole towatds ihe heel, upon both fides : it is more foft and higher raifed than the reft ot the fole. T}\&. Ruff. m V oc.
FRUSTUM (Cyd.) ^ Frustum of a cone. The cylinder generated by the revolution of the rectangle EBCF (fig. I I
- about one- of its fides EB, which is the height of the frujium
of a cone, the other fide BC being the radius of its grcateft bale, is to the frujium generated by the revolution of the tra- pezium EBCH, as the (quare of BC is to the rectangle contained under BC and EH, added to one third part of the fquare of the difference of thefe lines. Archimedes.
We have a general theorem in Mr. Mac Laurin's Trearifc of Fluxions, concerning the frujium of afphere, cone, fphe- roid, or conoid, terminated by parallel planes, when com- pared with a cylinder of the fame altitude, on a bafe equal to the middle feclion of the frujium made by a parallel plane. The difference between the frujium and the cylinder is al- ways the fame in different parts of the fame, or of fimilar folids, when the inclination of the planes to the axis, and the altitude of the fruftum are given.
Frustum of a parabolic conoid. In the parabolic conoid this difference vaniftes, the frujium being always equal to a cy- linder of the fame height, upon the fection of the conoid that bifefls the altitude of the frujium, and is parallel to its bafes.
Frustum of a fphere. In a fphere the frujium is always lefs than the cylinder by one fourth part of a right angled cone, of the fame height with the frujium, or by one half of a fphere of a diameter equal to that height; and this difference is al- ways the fame in all fpheres, when the altitude of the frujium is given.
In the cone, the frujium always exceeds the cylinder by one fourth part of the content of a fimilar cone that has the fame height with the frujium.
L Frustum
