14 



CHEMISTRY. 



Supcru! 

 phureird 

 hydrogen. 



Pi niphu- 

 n 1 of int- 



phur. 



hj a strong fetid smell, like that of rotten eggs. It 

 neither supports combustion, nor animal lite, lit 

 specific gravity, according to Kirwan, is 1.106 ; ac- 

 ording to Thenard, l.'J.'ll ; according to Davy, 

 1117. Water absorbs about its own weight of this 

 gas, and acquire* a fetid snvll, a sweetish nauseous 

 taste, and many of the properties peculiar to acids. 



\' -n this gas is set on tire, it burns with a reddish 

 blue colour, and deposits a quantity of sulphur. 

 When the electric spark is pasted through it, sulphur 

 is deposited, but the bulk of the gas is not altered. 

 Sulphur is also deposited when nitric acid is dropt 

 into water impregnated with it. When mixed with 

 oxygen gas, and burnt, the only substances formed 

 are sulphuric acid and water. Hence it is obvious, 

 that its constituents are sulphur and hydrogen. 



From the experiments of Mr Davy we learn, that 

 when sulphur is heated in hydrogen gas, a portion of 

 tulphureu-d hydrogen is formed, but the bulk of the 

 gas is not altered. Hence the specific gravity of the 

 gas obviously gives us the proportion of its consti- 

 tuents. It must consist of 



Sulphur 93.5 

 Hydrogen 6.5 



100.0 



Sulphur acts upon charcoal at a red heat. If a 

 quantity of charcoal be put into a porcelain tube, 

 and heated to redness, by passing it through a fur- 

 nace, and sulphur be made to pass through it while 

 in that state without any communication with the ex- 

 ternal air, a substance issues from the extremity of 

 the tube, which may be obtained by means of a 

 crooked glass tube luted tn the porcelain tube, and 

 plunged to the bottom of a glass vessel filled with 

 water. This substance is a liquid, colourless and 

 transparent when pure, but often tinged greenish 

 yellow. Its taste is cooling and pungent, and its 

 odour strong and peculiar. It does not dissolve in 

 water. Its specific gravity is 1.3. In an exhausted 

 receiver, or at the top of a barometrical tube, it as- 

 sumes the gaseous form. It burns very easily, and 

 detonates when mixed with oxygen gas and kindled. 

 It was first discovered by Lampadius, and Clement 

 and Desormes; and B<Tthol!et, junior, investigated its 

 properties. It is composed of sulphur and hydrogen, 

 but contains more sulphur than sulphurated hydro- 

 gen. It may therefore be called mper-sulphureted 

 hydrogen. 



Sulphur and phosphorus readily combine, and in 

 various proportions ; but the compound seems to be 

 most intimate when the weights of the two ingredi- 

 ents are equal. The combinations may be made by 

 mixing the two ingredients in a small phial and melt- 

 ing them together, or by cautiously heating them in 

 a flask filled with water. But the first method is less 

 hazardous ; for the compound acts upon the water, 

 and gases are formed, which sometimes occasion vio- 

 lent explosions. The compound has a yellowish 

 green colour : it may be distilled over in a glass retort 

 without decomposition. It has a tendency to the 

 liquid form, which is greatest when equal proportions 

 ef the constituents are used. It then remains liquid 



in the temperature of +1. When the sulphur pre- 

 dominates in this compound, it may be called phot- ol . 

 pfim-ft of sulphur; when the phosphorus, ndplmret ^ 

 of phosphor ut. It is very combustible, and often 

 takes fire spontaneously when exposed to the air. 



From the experiments of Claytield and Bcrthollet, 

 junior, there is reason to conclude that sulphur con- 

 tains a small quantity of hydrogen. 



SECT. V. Of Borncinm. 



This substance was discovered by Mr Davy, but it Boracium. 

 was first described by Thenard and Gay-Lussac. Mr 

 Davy has lately published a more detailed account 

 of its properties. To procure it, equal weights of How pro- 

 the metal called potassium and dry boracic acitl are cured, 

 to be put into a copper tube, and exposed for some 

 minutes to a slight red heat. When cold, the mass 

 is to be washed out with water, the potash saturated 

 with muriatic acid, and the whole thrown upon a 

 filter. An olive-coloured matter remains, which must 

 be washed and dried. It is boracium.* 



Boracium is of a dark olive colour, opake, brittle, Iis proper- 

 its powder does not scratch glass, it is a non-conduc- tu ' 

 tor of electricity, and has some resemblance to char- 

 coal. When heated to whiteness in a metallic vessel, 

 it remains unaltered, provided common air or oxygen 

 be excluded. After this process it sinks in strong 

 sulphuric acid ; but in its ordinary state it swims 

 upon that liquid. 



When heated in common air or oxygen gas, to a Boracic 

 temperature not quite so high as 600, it takes fire acid, 

 and burns with considerable brilliancy, somewhat like 

 charcoal, and is converted into boracic acid. By this 

 process, a portion of the oxygen disappears. Hence 

 boracic acid is considered as a compound of boracium 

 and oxygen. The exact proportion of the constitu- 

 ents of this acid have not yet been ascertained. Ac- 

 cording to Mr Davy's experiments, it is composed of 

 one part boracium, and two parts oxygen ; while 

 Thenard and Gay-Lussac consider it as a compound 

 of two parts boracium and one of oxygen. 



When placed in contact with chlorine, it burns 

 spontaneously with a white light, and is partly con- 

 verted into boracic acid, partly into a black matter 

 which is considered as an oxide of boracium. It burns 

 when slightly heated, and is converted into boracic 

 acid. It decomposes sulphuric and nitric acids with 

 the assistance of heat, and is converted into boracic 

 acid. When melted with sulphur and kept long in 

 contact with it, a kind of combination takes place as 

 the sulphur acquires an olive colour. It does not 

 combine with phosphorus. Whether it combines with 

 hydrogen and with charcoal, has not been tried. 



Potash and soda dissolve it both when liquid and 

 when melted with it in a crucible, forming pale olive 

 compounds, which give dark-coloured precipitate* 

 when treated with muriatic acid. It did not com- 

 bine with mercury by heat. 



Mr Davy has rendered it probable that it contain* 

 a little oxygen, and that, when deprived of this prin- 

 ciple, it combines with metals, and forms compounds 

 capable of conducting electricity. 



The French chemists have colled it tore. Sarm would be a better name than cither. 



