CHYMISTRY. 



It 



6x m* hydrogen gas. It is one of the constitu 

 ent parts of wafer ; for it has been completely 

 demonstrated by experiment, that water is com 

 posed of 85 parts by weight of oxygen, and 15 

 of hydrogen, in every Hundred parts of the fluid. 

 This gas was forrauily known by the name of 

 inflammable, air. It is distinguished among mi 

 ners by the name ofjfre-damp; it abounds in 

 coal-mines, and sometimes produces the most 

 tremendous explosions, it is incapable, by it 

 self, of supporting combustion, and cannot be 

 breathed without the most imminent danger. It 

 is the chief constituent of oils, fats, spirits, ether, 

 coals, and bitumen ; and is supposed to be one 

 of the agents which produce the ignes fatui and 

 the northern lights. It is the lightest of all pon 

 derable bodies ; being from twelve to fifteen times 



powerful antiseptic, or preserver from putrefac 

 tion. Meat which has been sealed up in it (says 

 Mr. Parkes) has been known to have preserved 

 its texture and appearance for more than twenty 

 years. There is no substance of more import 

 ance in civilized life than the different forms of 

 Carbon. &quot; In nature,&quot; says Sir. H. Davy, 

 &quot; this element is constantly active in an import 

 ant series of operations, it is evolved in fer 

 mentation and combustion, in carbonic acid ; it 

 is separated from oxygen in the organs of plants ^ 

 it is a principal element in animal structures ; 

 and is found in different forms in almost all the 

 products of organized beings.&quot; 



Sulphur is a substance which has been known 

 from the earliest ages. It was used by the an 

 cients in medicine, and its fumes have, for more 



lighter than common air. A hundred cubic in- than 2000 years, been employed in bleaching 

 ches of it weigh about 2 grains. On account wool. It is found combined with many mineral 

 of its great levity it is used for filling air-balloons. 

 In contact with atmospheric air, it burns with a 



pale blue colour. When mixed with oxygen gas, 

 it may be exploded like gunpowder, with a vio 

 lent report. CarbureUed hydrogen gas, which 

 u carbon dissolved in hydrogen, is that beautiful 

 gas, which is now employed in lighting our 

 streets, shops, and manufactories. 



Carbon is another simple substance extensively 

 diffused throughout nature. It is found pure and 

 solid only in the diamond; but it may be pro 

 cured in the state of charcoal, by burning a piece 

 of wool closely covered with sand, in a cruci 

 ble. Carbon enters into the composition of bi 

 tumen and pit coal, and of most animal and some 

 mineral substances ; and it forms nearly the 

 whole of the solid basis of all vegetables, from 

 the most delicate flower to the stately oak. It is 

 also a component part of sugar, and of all kinds 

 of wax, oils, gums, and resins. It combines 

 veith iron in various proportions, and the results 

 are cast iron and steel. Black lead is a corn- 

 position of nine parts of carbon to one of iron ; 

 and is, therefore, called a carburet of iron. Carbon 

 is indestructible by age, and preserves its iden 

 tity in all the combinations into which it enters. 

 Carbonic acid gas is a combination of carbon and 

 oxygen. It is found in a state of combination with 

 lime, forming limestone, marble, and chalk; and 

 may be separated from them by heat, or by means 

 of the mineral acids. This gas, which was for 

 merly called fixed air, is found in mines, caves, 

 the bottoms of wells, wine cellars, brewers vats, 

 and in the neighbourhood of lime-kilns. It is 

 unown lo miners by the name of the choke-damp, 

 and too frequently runs on deadly errands. It 

 extinguishes flame and animal life. It is the 

 heaviest of all the gases ; being nearly twice the 

 wei&amp;lt;;ht of common air, and twenty times the 

 weight of hydrogen. Tt may, therefore, be 

 poured from onu vessel to another; and if a 

 miall quantity of it be poured upon a lighted 

 taper, it will be instantly extinguished. It is a 

 14 



substances, as arsenic, antimony, copper, and 

 most of the metallic ores. It exists in many mi 

 neral waters, and in combination with vegetable 

 and animal matters, but is most abundant in vol 

 canic countries, particularly in the neighbour 

 hood of Vesuvius, Etna, and Hecla in Iceland. 

 It is a solid, opaque, combustible substance, of 

 a pale yellow colour, very brittle, and almost 

 without taste or smell. Its specific gravity is 

 nearly twice that of water ; it is a con-conduct 

 or of electricity, and, of course, becomes elec 

 tric by friction. When heated to the tempera 

 ture of 170 of Fahrenheit s thermometer, it 

 rises up in the form of a fine powder, which is 

 easily collected in a proper vessel, and is named 

 the flowers of sulphur. It is insoluble in water, 

 but may be dissolved in oils, in spirit of wine, 

 and in hydrogen gas. When sulphur* is heated 

 to the temperature of 302 in the open air, i 

 takes fire spontaneously, and burns with a pale 

 blue flame, and emits a great quantity of fumes 

 of a strong suffocating odour. When heated 

 to the temperature of 570, it burns with a bright 

 white flame, and emits a vast quantity of fumes. 

 When these fumes are collected, they are founa 

 to consist entirely of sulphuric acid; BO that sul 

 phur, by combustion, is converted into an acid. 

 It is the base of several compound substances. 

 It unites with oxygen, hydrogen, nitrogen, phos 

 phorus, the alkalies, the metals, and some of the 

 earths. This substance is of great importance 

 in medicine, as it is found to penetrate to the ex 

 tremities of the most minute vessels, and to im 

 pregnate all the secretions. It is also used in the 

 arts, particularly in bleaching and dying ; it forms 

 a very large proportion of gunpowder ; and one 

 of its most common, but not least useful proper 

 ties, is that of its combustibility, by which, with 

 the help of a tinder-box, light is almost instanta 

 neously produced. As this substance has not 

 yet been decomposed, it is considered by chy- 

 mists, in the mean time, as one of the simple 

 substances. 



