Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/768

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35. The long, narrow and thkkAeav'dfitcus. 36. The har- row-leav'd ligulated focus. 37. The fa focus with a very long and broad and tender leaf. 38. The five-leav'd dentatedjfo- cus. 39. The fmall focus with long cylindric and pointed branches. 40. The fucus with a fingle, long, and very broad leaf, rugofe in the middle. 41. The fea fucus with a long, broad, and very thick leaf. 42. The long, leafy, bfack fucus. 43. The fmall purple fea fucus with cylindric branches and leaves, 44. The green upright branched, cylindric, fpongy fucus. 45. The tall, not branched, green, fpungy, cylindric fucus. 46. The fmall fucus with cylindric and fiftulous leaves. 47. The flag's horn fa. fucus with globules at the ends of the branches. 48. The fine orbicularly fpreadingjfora; with fhort bifid or trifid cylindric fegments. 49. The fucus refembling filk or cloth in its texture. 50. The white narrow-leav'd, compreffed, fcrupofe fucus with the extremities of the branches feemingly cut ofF. 51. The ramofe fa fucus. 52. The fol- liculated fucus with ferrated leaves, called the cut-Ieav'd fea lentils. 53. The folliculated fucus with toad flax leaves.

54. The American fucus with broad, fhort, and ferrated leaves.

55. The American fucus with very fhort broad leaves. 56. The fmall denticulated triangular fucus. 57. The fmall white cy- lyndric, fungous, coral loidey«a<j with few fegments. 58. The lettuce-Ieav'd fucus, or lactuca marina, called oyfter-green. 59. The endive-leav'd fa fucus. 60. The tubular fucus of the fhape of guts, commonly called the fea chitterling. 61. The coronopus-leav'd fucus. 62. The fa fucus, called rocella t and fea dyer's-wecd, or alga tin&oria. 63. Theverrucofe rocella. 64. The great fpiralleav'd fea fucus. 65. The fmaller fpiral- leav'd fa fucus. 66. The turkey-feather fa fucus. 67. The round- Ieav'd fa fucus. 68. The fmall American opuntia-like

fucus. 69. The hand-fhap'd fucus. 70. The feather fucus. 71. Thegreat horned fafoms. 72. The broad-leav'd denta- ted purple fa fucus. 73. The elegant finely divided purple fucus. 74. The purple ferrated fa fucus. 75. The fpongy felinoide fa fucus. 76, The prickly, undulated, river fucus ; and, 77. The low fimbriated and curled Italian fucus. Teurn. Inft. p. 566.

Mr. Reaumur has difcovered, that all the focus's produce regu- lar flowers and feeds, and that in the fame regular manner. The flowers Brand all over the leaves from the origin of them at the root to their utmoft extremities, only the ribs in the middle are free from them. Every flower is compofed of a clufter of fmall and extremely flender threads. Thefe are ufually all of the fame length in the fame flower, but they are fo numerous as not to be eafily counted ; the longeft of thefe threads are not above one twelfth of an inch in length, and the reft are not half fo long. They all iffue out of a fmall hole in the leaf, which ferves as a fort of cup to them. The threads are too feeble to fupport their own weight in the air. When the fea has left the plants, they are all found lying flat upon the leaves; though while the water covers them, they ftand fomewhat eredt. They are not terminated at the top by apices containing a farina ; but they may very eafily con- tain that powder in their whole fubftance, and throw it off as foon as they expand themfelves. They are difpofed with no fort of regularity on the leaves ; for in fome places they ftand very clofe together, in others they are placed at much greater diftances. They grow equally on both fides of the leaves ; but the fame flower never perforates the leaf, but all its parts ap- pear on the fame fide. The flowers are much more eafily difcerned on the plant when it is dry, than while it is moift ; for when dry, the filaments that compofe them are white; whereas when moift, they are of a deep brown, like the leaves on which they ftand. Of all the flowers which cover thefe plants, there are none that produce feeds but thofe which are placed near the extremities of the leaves, and not all of thefe. In thofe places where the feed is beginning to form itfelf, the extremity of the leaf f wells, and forms a fort of capfule, which contains the fruit, while the reft of the leaf retains its former thinnefs. When the flowers are fallen, the holes in the leaf, which ferv'd them for cups, become eafily vifible in the places where the thicknefs happens, and where the feeds are to be lodg'd ; and the margin of each hole is furrounded with a little circular protuberance, which ftands out beyond the reft of the furface. The fwelled ends of the leaves often grow to half an inch in thicknefs, and ufually terminate in two horns, which form an acute angle ; and the rib of the leaf is not vifible in thefe fwoln parts. When thefe are cut open, whether it be tranfverfely or horizontally, they are found filled with a thick vifcous liquor, and in this are feen feveral roundifh bodies of about a twenieth part of an inch in length ; they are of a red- difh colour, and are eafily diftinguifhed, and are all found to be fixed to the fides of the leaf. Thefe are what Dr. Robin- fon, who feems to have been the firft perfon who difcover'd them, took for the feeds ; and they have really much the ap- pearance of naked feeds; but, when clofely examined, they are found to be in reality capfules containing each a great num- ber of minute round feeds, which are faftcn'd to their fides, as they were to the fides of the tumor in the leaf: and thefe fmaller capfules are in the fame manner with thofe full of a transparent vifcous liquor.

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Though thefe capfules appear at firft fight plain roundifh bo- dies; yet when more nearly examin'd, they are found to be rather ftiaped like glafs bottles with fhort necks, the neck be- ing fixed into the fubftance of the leaf, and its extremity form- ing the protuberant circular rim that fur rounds the little hole in the leaf, which had ferved as a cup to the flowers. See Mem. Acad. Far. 1711, where we have figures of the fucus. The antients ufed a purple fea plant to dye woollen and linnen things to that colour, and called it fucus. The dye was very beautiful, but not lafting ; for it foon began to change, and in time went wholly off. This is the account Theophraftus gives of it.

The women of thofe times ufed alfo a thing called focus to ftain their cheeks red ; and many have fuppoied; from the fame word exprefling both, that the fame fubftance was ufed on both occafions. But this, on a ftri&er enquiry, proves not to be the cafe. The Greeks called every thing fucus that would ftain or paint the flefh. But this peculiar fubftance us'd by the women to paint their cheeks, was diftinguifhed from the others by the name rixion among the more correct wri- ters, and was indeed a root brought from Syria into Greece on that occafion. The Latins, in imitation of the Greek name, called this plant radicular and, as Pliny has mention'd it, it

' is not improper to obferve, that he has very erroneoufly con- founded it with the radix lanaria oxjlruthlon of the Greeks. The word focus was in thefe times become fo univerfal a name for paint, that the Greeks and Romans had di fucus metallkus, which was the cerufs or white lead ufed for painting the neck and arms white ; after which they ufed the purpurifluni, or red fucus of the rizium, to give the colour to the cheeks. They alio in after-times ufed a peculiar focus or paint for this purpofe prepared of the creta argentaria, or filver chalk, and fome of the rich purple dyes that were in ufe in that time ; and this feems to have been very little different from our rofe pink, a colour commonly fold at the colour fhops, and ufed on like occafions.

Fucus Palmatus, banded Fucus. The name given to a fpeeies of fa fucus, diftinguifhed from the reft by its having no Italk, its leaves being divided in the manner of a hand, and its ex- tremities divided into many curl'd fegments. It is common on almoft all the fea coafts of Europe, and is one of the feve- ral fpeeies of fea plants in which Mr. Reaumur has difcover'd regular flowers and feeds. They are in this fpeeies however fo fmall, as to require the afliftance of a microfcope to difco- ver them ; though after they have been once feen in that manner, as is the cafe in many microfcopic objects, they may then be eafily diftinguifhed by the naked eye. This plant is faften'd to fome ftone by a round root, from which there arife four or five leaves, which at about an inch diftance from the root divide into a number of branchings which conftitute the whole plant. This fpeeies carries its feeds at the extremities of the leaves, where they are inclofed in the interior fubftance of the plant ; and nothing is to be difcover'd on the furface without the afliftance of glades, unlefs it be that the leaves are of a fomewhat more dusky hue there than elfewhere. With the help of glafles this obfeurity is found to be caufed by a number of fmall opake bodies; and to diftinguifh thefe well, the part muft be examined by holding it againft the light, and even in this examination the furface of that part of the plant does not appear different from the reft, nor can there be dif- tinguifhed any mark of the filamentous flowers of the common fpeeies, nor any fign of the protuberances made by the necks of the capfules, as is the common cafe. When this obfeure part of the plant is opened, there appears a number of fmall round and hard reddim feeds; there are ufually about twenty of thefe in every extremity of a leaf, and as the leaves are ten- der, they may be crufhed under one's nail, and by this means the feeds may be diftinguifhed from the fragments of the bruifed plant by their colour. Notwithftanding the fmallnefs of thefe bodies however, it is much to be doubted whether they are not capfules, or feed vefiels, rather than fingle feeds ; fince in all the larger focus's the feeds are found of an extreme fmallnefs inclos'd in capfules. An inftance of this may be feen in the focus polyfclndes. Mem. Acad. Par. 17 12. See Polys- chides.

Fucus polyfcbides. See Polvschides.

Fucus thermallsy in botany, the name of a remarkable fpeeies of plant, found only in the hot water fprings. It was firft dif- covered by Monf. de Montefquieu, in the great bafon, at the boiling fpring in Gafconv ; he was not able to difcover that it produced either flowers or feeds. Its fubftance is intirely com- pofed of fmall bladders full of air, the furfaces of which are reticular, as worked in the manner of a coarfe canvas. It is obferved to grow only in the hotteft waters.

FUDDER, among the miners, a load of lead, which is eight pigs, or fixteen hundred weight. May's Englifh Words, p. 19.

FUEL, (Cyd.) in chemical operations. - — A great deal of nicety is required in choofing the proper fuel to"raife and continue the feveral degrees of fire. The natural heat of the fummer fun is fufficient for infolations. A fpirit lamp may be made to give the next degree of heat to this, which may be much aug- mented