SULPHUR. '^^ 



Sulphur forms six compounds with oxygen, of which the most im- 

 Dortant are sulphurous and sulphuric acids. 



Sidphurous omcU SO -the product when sulphur is burned in 

 the open air or in dry oxygen; prepared conveniently by the action 

 of sulphuric acid on mercury or copper ; a part of the acid is decom- 

 posed; yielding up sulphurous acid and oxygen ; the oxygen uniting 



with the metal. . j -^toof^. 



Prop —Colourless; of a pungent, suffocating odour, and acid taste, 

 sp sr 2-2105 ;— is condensed into a liquid at 45° by a pressure of 

 two atmospheres, and at 0° under a pressure of one atmosphere ;-a 

 non-supporter of combustion, and a non-combustible ;— cannot sup- 

 port respiration ; water at 60° absorbs 32 times its volume ; possesses 

 bleaching properties; its solution first reddening and then bleachmg 

 litmus Its salts are X^xm^^ sulphites : they are not of much im- 



SuMiuricacid.^O^—'^no^T^ in commerce as o^/o/7J^^r^o/• may 

 be procured in two modes ; first, by exposing the protosulphate of 

 iron (green vitriol) to a red heat, by which the sulphuric acid is 

 driven off and condensed, and the peroxide of iron remains Ihe 

 acid thus procured is an oily brown liquid, of a sp. gr. of 1-9, lummg 

 in the air and very corrosive ; it is known in commerce ^^fwning 

 sulphuric acid, or acid of Nordhausen, from the place of its manu- 



The 'second method is the one usually adopted. It depends upon 

 the fact that when sulphurous and nitrous acid are present along 

 with some water, the sulphurous acid takes oxygen from the nitrous 

 acid, the first becoming sulphuric acid, and the last deutoxide of m- 

 trogen The mode adopted is the following : a mixture of sulphur 

 and nitre is exposed to heat in such a manner, that the vapours are 

 carried into a leaden chamber, upon the bottom of which is a stratum 

 of water. The nitric acid of the nitre gives up oxygen to some ot 

 the sulphurous acid, thereby converting it into sulphuric acid which 

 immediately combines with the potassa ; the greater part of the sul- 

 phurous acid enters the leaden chamber when it comes in contact 

 with deutoxide of nitrogen, atmospheric oxygen, and watery vapours 

 forming a white crystalline compound, believed to be^composed of 

 sulphuric acid, hyponitrous acid, and water. When this solid falls 

 into the water on the floor of the leaden chamber, it is decomposed 

 into sulphuric acid, (which is dissolved by the water,) nitrous acid and 

 deutoxide of nitrogen. The nitrous acid thus set free as well as 

 that produced by the reaction of atmospheric oxygen ori the deutoxide 

 of nitrogen, is again mingled with sulphurous acid and watery 

 vapours as before, and gives rise to the formation of another portion 

 of the crystalline compound, which, in its turn, becomes decomposed 

 on falling into the water. When the water in the leaden chamber 



