FULGURITES. 



FUMARIA. 



discovery. Strange to say, however, many travellers deny altogether 

 the luminosity of the Lantern-Fly, whilst others as strongly assert 

 it. It is probably a sexual peculiarity, and only exhibited at certain 

 periods in the animal's life. 



FULGURITES are vitrified sand-tubes, supposed to have originated 

 from the action of lightning ; they are called by the Germans 

 Blitzrohre. 



These tubes were discovered in the year 1711 by the pastor 

 Herman, at Mussel, in Silesia ; and they were again discovered in 

 1805 by Dr. Hentzeu, in the heath of Paderborn, commonly called 

 the Senue, and he first attributed their formation to the agency of 

 lightning. 



These tubes have since been found in great numbers at Pillau, 

 near Kb'nigsberg, in Eastern Prussia ; at Nietleben, near Halle on 

 the Saale ; at Drigg in Cumberland, and some other places. 



At Drigg, the tubes were found in the middle of sandbanks, 40 feet 

 high, and very near the sea. In the Senne they were most commonly 

 found on the declivities of mounds of sand, about 30 feat high ; but 

 sometimes in cavities, which are stated to have been hollowed in 

 the heath, in the form of bowls, 200 feet in circumference, and 12 to 

 1 5 feet in depth. 



These tubes are nearly all hollow. At Drigg their external diameter 

 was 2J inches; those of the Senne, reckoning from the surface, are 

 from one quarter to seven lines internal diameter; but they narrow 

 as they descend lower, and frequently terminate in a point : the 

 thickness of the tube varies from half a line to an inch. 



These tubes are usually placed vertically in the sand ; but they 

 have been found at an angle of 40 degrees. Their entire length, 

 judging from those which have been extracted, is from 20 to 30 feet ; 

 but frequent transverse fissures divide them into portions from half 

 an inch to 5 inches in length. 



Usually there is only one tube found at a place ; sometimes how- 

 ever, at a certain depth, this tube divides into two or three branches, 

 each of which gives rise to small lateral branches, from an inch to a 

 foot in length ; these are conical, and terminate in points, inclining 

 gradually to the bottom. 



The internal part of the tubes is a perfect glass, smooth and very 

 brilliant, resembling hyalite. It scratches glass, and gives fire with 

 steel. All the tubes, whatever may be their form, are surrounded by 

 a crust composed of agglutinated grains of quartz, which have the 

 appearance, when examined by a glass, of having undergone incipient 

 fusion. 



The colour of the internal mass of the tubes, and especially that 

 of the external parts, depends upon the nature of the sandy strata 

 which they traverse. In the superior beds, which contain a little 

 soil, the exterior of the tubes is frequently black ; lower down the 

 colour of the tube is of a yellowish-gray ; still lower, of a grayish- 

 white ; and lastly, where the sand is pure and white, the tubes are 

 almost perfectly colourless. 



That the cause of these tubes is correctly attributed to lightning is 

 shown by some observations presented to the Royal Society, in 1790, 

 by Dr. Withering. On opening the ground where a man had been 

 killed by lightning, the soil appeared to be blackened to the depth 

 of about 10 inches; at this depth, a root of a tree presented itself, 

 which was quite black ; but this blackness was only superficial, and 

 did not extend far along it. About two inches deeper, the melted 

 quartzose matter began to appear, and continued in a sloping direction 

 to the depth of 18 inches ; within the hollow part of one mass, the 

 fusion was so perfect, that the melted quartz ran down the hollow, 

 and assumed nearly a globular figure. 



Professor Hagen, of Konigsberg, has made a similar observation. 

 In the year 1823 the lightning struck a birch-tree at the village of 

 Kauschcn. On cautiously removing the earth, Professor Hagen found, 

 at the depth of a foot, the commencement of a vitrified tube, but it 

 could not be extracted from the sand in pieces of more than two or 

 three inches in length ; the interior of these fragments was vitrified, 

 as usual ; several were flattened, and had zigzag projections. 



It is also to be observed, that Saussure found on the slaty horn- 

 blende of Mont Blanc small blackish beads, evidently vitreous, and 

 of the size of a hemp-seed, which were clearly the effects of light- 

 ning. Mr. Ramond has also remarked on the Pic du Midi, in the 

 Pyrenees, some rocks, the entire face of which is varnished with a 

 coating of enamel, and covered with beads of the size of a pea ; the 

 interior of the rock is totally unchanged. 



FULICA. [RALLID.E.] 



FULIGULA, FULIGULIN^E. [DUCKS.] 



FULLERS' EARTH, a Mineral product, formerly much used in 

 the fulling of cloth, whence it derives its name. It occurs massive, 

 and is usually of a greenish-brown or dull gray colour; sometimes it 

 is nearly of a slate colour. It is opaque, dull, and its specific gravity 

 is 1 -8 to 2-2. Greasy and soft, yielding to and polished by the nail. 

 Fracture uneven, earthy ; in water it breaks down into a soft pulpy 

 mass. Before the blow-pipe it fuses into a white blobby glass. 



It is found at Nutfield, near Reigate, in Surrey, and occurs in 

 regular bd near the summit of a bill, between beds of sand or 

 undstone, containing fossil wood, cornua ammonis, &c. There are 

 two distinct beds of Fullers' Earth ; the upper has a greenish colour, 

 1* 6 feet in thickness, and rests upon the other, which has a bluish 





tint, and is 11 feet thick; in these beds, but especially in the latter, 

 there are found considerable masses of sulphate of barytes, frequently 

 in regular crystals. Fullers' Earth is also found iu Kent, Bedford- 

 shire, Bath, Nottinghamshire, and Sussex. It is met with also ill 

 Styria, Saxony, and some other places. 



According to Dr. Thompson's analysis, this substance consists of 



Silica 44 



Alumina 23'06 



Lime 4'08 



Magnesia 2 



Protoxide of Iron 2 



Water 24 '95 



100-09 



Dr. Thomson observes that, allowing the lime, magaesia, and 

 protoxide of iron to be in the state of silicates, and as mere acci- 

 dental constituents, Fullers' Earth is a hydrous bisilicate of alumina, 

 consisting of two equivalents of silica, one equivalent of alumina, 

 and two equivalents of water. 



FUMA'RIA (from the Latin Fttmus, smoke, in allusion to the 

 unpleasant smell which it exhales ; the French, with the same meaning, 

 call it Fumeterre, and hence our English word Fumitory), a genus of 

 plants the type of the natural order Fumariaccoit It has 4 petals, the 

 upper one spurred at the base, 2 sepals, diadelphous stamens, fruit inde- 

 hiscent and 1-seeded. There are about 12 species of Fumaria, which are 

 smooth slender herbs, with small racemose white or purplish flowers. 



1 3 2 



Corydalis hitea. 



I, the two sepals, stamens, and pistil ; 2, a longitudinal section of the ovary ; 

 3, a longitudinal section of a seed, showing the ovary : all more or less 

 magnified. 



F. capreolata, Rampant Fumitory, has ovate acute sepals, toothed, 

 as broad as the corolla, and half its length ; globose emarginate fruit ; 

 bracts about a third shorter than the fruit-stalks. It is a climbing 

 plant, and has cream-coloured flowers tipped with red or purple. 



F. officinalis. Common Fumitory, has ovate lanceolate sepals, 

 narrower and two-thirds shorter than the corolla, broader than the 

 pedicel ; fruit globose, truncate, slightly emarginate ; bracts two or 

 three times shorter than the fruit-stalks. It grows in corn-fields and 

 cultivated land throughout the world, and is plentiful in Britain. The 

 flowers are of a pale-red colour, deep-red at the summit, with a 

 green keel to the upper and under petals. The leaves are succulent, 

 saliue, and bitter, and the expressed juice is recommended as a 

 remedy in cases of hypochondriasis and cachectic states of the body. 

 It is said to correct acidity and strengthen the stomach. Boerhaave 

 used to prescribe it in black jaundice and bilious affections. It has 

 also gained some reputation as a cosmetic. Dr. Cullen recommends 

 an infusion of the leaves in cutaneous disorders, and lie also advises 

 the use of it as a tonic whenever bitter remedies are desirable. 



F. micranlha is distinguished by its sepals being orbicular dentate, 

 broader than and nearly half as long as the corolla ; fruit globose, 

 slightly pointed ; bracts longer than the fruit-stalks. This species is 

 found both in England and Scotland, and has pale purple flowers in 

 dense spikes. 



P. fa.rvifl.ora has ovate sepals as broad as the corolla and about two- 

 thirds shorter. It greatly resembles F. offi.cina.lit, but is smaller in all 

 its parts. The flowers are of a pale-red colour. It is found in 

 Kent, and is also very common in the East Indies, where it is used 

 as a medicine. The leaves have a bitter taste, and Dr. Whitlaw Ainslie 

 mentions it in his ' Materia Medica of Hindostau.' The Mohammedans 

 employ it as a diuretic, and in maniacal cass. 



