11s THE ANSLYST, SULPHUR I N GAS. THE vexed question of the amount of sulphur impurities to be allowed in gas, which for twelve months at least has been practically settled in London by the defeat of the two bills brought in by the Crystal Palace Gas Company and the Gas Light and Coke Company, has been raised at Naidstone, where the gas on two or three occasions appears t o have contained from 35 to 45 grains of sulphur per 100 cubic feet; or, in other words, t o have been in this respect as bad as absolutely unpurified gas.Complaints were naturally made on the subject, and the enginecr of the Naidstone Gas Works presented a report to the directors of the company, containing some statements which, to those who are familiar with the evidence recently given before the select committees of the House of Commons, must appear to be of a most remarkable character.Thus, this gentleman says ‘( the evidence given on that occasion by the chemists, who are alike the most eminent of the day and the most experienced in respect to coal gas, has gone to prove that a quantity of these compounds, up to about 35 or even 40 grains per 100 cubic feet, is not injurious to health; and that a partial removal is not worth the trouble and expense incurred.” It is certainly somewhat singular that, if the evidence of these chemists did prove this fact, the select committee should neverthelesg, as reported in our number for July, page 67, have thrown out both the bills, aod there-THE ANALYST.119 fore kept the companies still under restrictions in regard to sulphur compounds, There is no doubt that some evidence was given of the character alluded to in the engineer’s report, but this evidence was so emphatically contradicted by chemical evidence on the other side that the committee had no other course before them but to reject the gas companies’ proposals.We purpose in our next number, if space alIows, making further reference to this subject, with a special view to pointing out the character of the products which are produced during thc combustion of ordinary coal gas containing sulphur. It is quite evident that such a paper is needed, not perhaps so much for thc enlightenment of analysts RS for the information of those quasi chemists who put themselves forward to advise public bodies cin such points.Thus we find in this case an argument extending orer some half column of letterpress t o prove that 40 or 50 grains per 100 cubic feet cannot be injurious, because it only forms about 0.18 per cent. by weight of the gas which is burned, ignoring entirely the fact that this gas in its combustion produces a t least three separate ingredients in considerable quantity, namely-water, carbonic acid, and sulphuric acid. What can slnx percentage composition possibly have to do with a case of this kind, where the injury is done solely by the sulphuric acid which is formed? Impure gas has nearly as much influence on the death rate as impure water.