Some few weeks ago it was my pleasure to read a paper before the Western Ophthalmological, Otological, Laryngological and Rhinological Association, calling attention to the effect of natural gas upon the conjunctiva. I now desire, in a general way, to show wherein the natural gas from the Indiana field is a potent factor in causing catarrhal inflammation of the whole pneumatic system, with special reference to the Eustachian tube.
The gas from Indiana differs from that of the New York or Pennsylvania field, in that it contains sulphuretted hydrogen, and in burning the process of combustion is not so complete. Eighty-five per cent. of the natural gas is marsh gas, which is composed of 75 per cent, by weight of carbon and 25 per cent, of hydrogen. The products of combustion, which differ in every case, are carbon dioxid, water vapor, sulphur dioxid, trioxid, nitrogen oxids and ammonia sulphate. The