TRANSACTIONS OP THE SECTIONS. 81 



at the upper portion of the tower, any gas which might otherwise escape was ex- 

 posed to tlie absorbing power of uuacidiilated water. In 1838, a French house, 

 Messrs. Taix and Co., of Marseilles, obtained a monopoly from the King of Sicily 

 for the export of sulphur. This caused an advance in price to £14 per ton, from 

 the previous rate of £5 per ton. It was found that in our Cornish mines and in 

 those of Wicklow in Ireland, we possessed an inexhaustible supply of sidphur iu 

 the form of pyrites ; and our practical chemists soon availed themselves of this 

 source for the manufacture of sulphuric acid. In working with pyrites it was found 

 that this mineral contained sulphide of copper as well as sulphide of iron, and at 

 an early period he commenced to extract the copper from the burnt residuum by 

 smelting. At the present time, the products obtained by the soda manufacturers 

 were soda ash, worth £8 per ton ; soda crystals, about £4: 10s. per ton ; bleaching 

 powder, £9 per ton ; bicarbonate of soda, £10 per ton ; whilst the cost of raw 

 materials, now used in Lancashire, is — sulphur, £8 per ton, for which was substi- 

 tuted pyrites at a cost equivalent to £5 per ton ; common salt, 8s. ; limestone, 6s. 8d, ; 

 fuel, 6s. per ton. Thus, with a reduction in the cost of raw materials not more 

 than equal to 10 per cent, the public was supplied with the products of the soda 

 manufacturer at a reduction of at least 60 per cent. As nearly as he could obtain 

 information, there were 50 establishments in Great Britain in which soda was 

 manufactured by Le Blanc's process, producing about 3000 tons of soda ash, 2000 

 tons of soda crystals, 250 tons of bicarbonate of soda, and 400 tons of bleaching 

 powder per week. The total amount of these products might be estimated as 

 exceeding two millions sterling, which was so much entirely added to the annual 

 income of the coimtry, excepting about £100,000 paid for materials obtained from 

 other countries. He must not omit to notice the prospect of a new market for 

 British-made soda which had been opened by the successful labours of Mr. Cobden, 

 in negotiating the commercial treaty with the French government. 



Many attempts had been made to supersede Le Blanc's process, by some more 

 direct means of operating on salt, so as to eliminate its soda at once. Up to the 

 present time, the result of all these attempts had been the wastefid expenditure of 

 large sums of money. Two-fifths of the total cost for raw materials was incurred 

 for pyrites from which to procure a supply of sidphur ; and it was a well-known 

 fact that more than nine-tenths of this sidphur was retained in the material called 

 " alkali waste," which was thrown away by the manufacturer. Thus was presented 

 a problem which, if it coiUd be solved, would effect a large reduction in the cost of 

 soda. Many chemists, both scientific and practical, had given a gi-eat amount of 

 attention to the subject. He had been so unfortunate as to be amongst the number, 

 as he had devoted a great proportion of his time, during a quarter ot a century, and 

 a large amount of both money and labour to this hitherto delusive subject. He 

 commenced by demonstrating, in 1838, that one equivalent of carbonic acid would 

 decompose one equivalent of sulphide of calcium, producing monocarbonate of lime 

 and sulphide of hydrogen. This decomposition was contrary to the received views 

 of scientific chemists of that day, as it was held that an excess of carbonic acid was 

 needful to efi'ect the perfect decomposition of sidphides. He was convinced that 

 whenever the utilization of the sidphur in alkali waste should be eflected, it would 

 be by means of this action of carbonic acid. He demonstrated also, at the same 

 time, that one equivalent of carbonic acid would decompose one equivalent of sul- 

 phide of sodium, producing monocarbonate of soda and sulphide of hydrogen. His 

 present impression was that Le Blanc's processes would be modified by the omis- 

 sion of lime when decomposing sulphide of soda, thus producing sulphide of 

 sodium ; and that the carbonic acid evolved by this decomposition would be applied 

 to decompose the sulphide of sodium, producing carbonate of soda, and eliminating 

 sulphide of hydrogen, which would be absorbed by peroxide of iron, and the pro- 

 duct used in the manufacture of sidphuric acid. He had proved the correctness of 

 all those decompositions and actions ; but the ideas had still to be worked into a 

 practical operation. 



On the Construction of Gas-Burners for Chemical Use. 

 Bi/J.J. Gbiffin, F.CS. 

 The authorexhibitedaseriesof gas-burners adapted toproduce the difierent degrees 

 of heat that are required for the usual operations ox the experimental chemist. 

 1861. 6 



