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— Clafs and order, Pentandr'ia Moiiogynia. Nat. Ord. 

 Dumofaf Linn. Rhcinmi, .lufl'. 



Gen. Ch. Cal- Perianth inferior, of one leaf, cup-(haped, 

 with iive equal, triangular, deciduous, marginal fegments. 

 Cor. Petals five, fpatulate, inferted into the rim of the 

 calyx, alternate with its fegments, and rather longer. 

 Stam. Filaments five, awl-lhaped, oppofite to the petals, the 

 length of the calyx ; anthers of two round lobes. Pifl. 

 Germen fuperior, invefted below with the tube of the calyx, 

 nearly globofe ; i^yle (hort, cloven half way down ; ftigmas 

 two, divaricated, acute. Perk. Capfule globular, of one 

 cell, and two valves ; fplitting at the bafe ; crowned at 

 the fummit with an elliptic-oblong, flat, coriaceous, ribbed 

 wing, many times longer than ,the capfule. Seed folitary, 

 globofe. 



EfT. Ch. Calyx cup-(haped, with five deciduous fegments. 

 Petals five, oppofite to the ftamens. Capfule of one cell, 

 crowned by an elongated wing. Seed folitary. 



Obf. Gasrtner did not fee the capfule in a Sufficiently ad- 

 vanced ftate to difcover that it has really two valves, which 

 feparate at the bafe, continuing connected at the apex by 

 their long coriaceous wing, in which the mofl remarkable 

 charafter of the genus confifts. Thejloivers are occafionally 

 dioecious, from the imperfeftion of one or other organ of 

 impregnation. 



I. V. madernjpatana. Yerra Chirtaly of the Te- 

 lingas. Willd. n. i. Roxb. Coromand. v. i. 55. t. 76. 

 (Funis viminalis ; Rumpli. Amboin. v. 5. 3. t. 2.) — Native 

 of forefts and uncultivated places, among the mountains of 

 Hindooftan and Ceylon, and of rocky thickets on the fhores 

 of Amboyna, flowering in the cold feafon. The Jlem is 

 woody, climbing to a great extent, with long, round, 

 pliant, tough, leafy, often downy, branches. Leaves al- 

 ternate, on (hort ilalks, ovate, bluntilh, two or three inches 

 long, coriaceous, more or lefs obfcurely crenate, foldom 

 quite entire, fmooth or minutely downy, furniflied with one 

 midrib, and many tranfverfe ones, connefted by extrernely 

 fine parallel veins. Floivers very numerous, fmall, greenifh- 

 white, in large, terminal, compound panicles, their fcent 

 highly offenfive, refembling Sterculia fatida. Wing of the 

 capfule entire, greenilh-yellow, (lightly downy, above an inch 

 in length. — Willdenow, according to Poiret, has diftin- 

 guiflied two fpecies of this genus, in the new Tranfaftions 

 of the Berlin Society ; one having entire and fmooth, the 

 other crenate and downy, leaves. But we are perfuaded, 

 from an examination of wild fpecimens from Roxburgh and 

 Koenig, that thefe characilers are variable. 



VENTILATION of Mines, comprifes the various 

 modes by which impure air is removed, and a current of 

 atmofpheric air propelled through the fubterranean open- 

 ings and pafTages of mines. The health, the faiety, and 

 lives of a very large and induftrious clafs of the community 

 depend on the regular ventilation of mines ; yet the apphca- 

 tion of the principles on which this fliould be undertaken 

 has been but imperfeftly underftood, and it is but very 

 recently that the fubjeft has engaged the attention of men 

 of fcience. Since the conftitution of the atmofphere was 

 afcertained, ( fee Atmosphere, ) it is well known that the 

 one-fifth part of it, or the oxygen gas, is elfentially necef- 

 fary to fupport the prccefFes of refpiration or combuftion, by 

 which it undergoes a chemical change, and is converted into 

 carbonic acid gas, a gas deftruftive of animal life, and in 

 which flame is infl;antly extinguiftied. It is alio as well 

 known, that the remaining four parts of the atmofphere, or 

 the azote, are equally deftruftive of life, and incapable of 

 fupporting flame : hence the neceffity of ventilation, or a 

 regular fupply of frelh air, in all confined fituations, where 



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men are to labour or exifl:, is very eafily explained. Befides 

 the deftruftion of oxygen gas by refpiration or combudion^ 

 which takes place in confined apartments above ground, 

 there are other caufes that render the air impure in almoft 

 all fubterranean paffages or mines, through which there is 

 not a regular current of wind conftantly pafGng. The 

 caufes by which the air in mines is rendered impure, or 

 defl:rudtive of animal life, are of three kinds. Firft, the 

 refpiration of men and horfes in the mine, and the com- 

 buftion of the lamps, &c ; fecondly, the produftion and 

 evolution of carbonic acid gas in the beds or fi;rata in which 

 the mine is fituated ; and thirdly, the production of carbu- 

 retted hydrogen or inflammable gas. For the properties 

 of thefe gafes, fee Gas. The two former fources of impu- 

 rity are much lefs deftruftive of life than the latter, the in- 

 flammable gas or Jire-damp of the miners : when this becomes 

 mixed to a certain degree with the air of the mine, it ex- 

 plodes with great violence on the appi'oach of a lamp or 

 candle, and occafions the moft fatal accidents, deftroying all 

 the vital air in the mine, and burning or fuffocating the 

 workmen. By explofions of this nature, it was efl;imated 

 that not lefs than fix hundred perfons periflied during the 

 years 1813 and 18 14, in the coal-mines on the rivers Tyne 

 and Wear, in Northumberland and Durham ; and the de- 

 ftruftion of human life in other coal dillrifts has been per- 

 haps equally great, in proportion to their extent. In the 

 ventilation of mines, where the air is impure from refpira- 

 tion, combuftion, or the evolution of carbonic acid gas, 

 calkd by the miners choak-datnp, the objeft of the miner is 

 fimply to introduce a current of frefti air through the works ; 

 but befides the difficulties to be overcome in effefting this, 

 where the works areextenfive, the miner who has to combat 

 with the fire-damp muft guard againft the greater evil of an 

 explofion, to which he is almoft conftantly expofed. 



In the working of metallic mines, the veins being gene- 

 rally nearly vertical, the currents of water, or the natural 

 paflages, aided by the varied temperature of the mine, are 

 frequently fufiicient to infure the circulation of air ; and 

 thefe mines are very rarely affefted by the produtlion of the 

 fire or choak damp. It is principally where a fhaft or well 

 is funk, or a horizontal paffage or gallery is made, that 

 any means of artificial ventilation are neceflary. The moft. 

 obvious remedy, and that which is moft frequently reforted 

 to, is opening a communication with fome other part of the 

 mine, or with the furface ; and when this is done, the ventila- 

 tion is found to be perfeft by the ruftiing of the currents, 

 which often takes place with confiderable force, from the 

 diff^erent degrees of temperature in the lower and upper air, 

 and thefe currents change their direftion as the temperatures 

 above and below alternate. The great objcftion to this 

 mode is the expence with which it is commonly attended 

 wherever the gallery is at a great depth, and the intervening 

 rock of a very hard kind, and where a fliaft is merely wanted 

 to fupply air, and not for the pafiage of the water. To 

 avoid this, the fhaft or level is fometimes divided into two 

 difljiiA parts, communicating near the part intended to be 

 ventilated, fo that a current may be produced in oppofite di- 

 reftions on each fide of the partition; and this is often 

 eff'eftual to a certain extent. It has, however, its limits at 

 no very great diftance, and the current is but a feeble one, 

 from the nearly equal temperature of the air on each fide of 

 the partition. 



The other mode employed is to force air down tubes 

 with a large pair of bellows worked by the hand, or by 

 boxes or cylinders of various forms placed on the furface, 

 with a large opening againft the wind, and a fmaller one 

 communicating with the air-pipes by a cylinder and pifton 

 4 Z 2 working 



