574 NATTJEAL GAS AT HEATHPIELD (sUSSEx). [Aug. 1 898,. 



the surface beneath ice was interesting. But would it be easy 

 to get areas still enough to freeze, where the absence of all 

 surface-generated marsh-gas could be guaranteed? 



Mr. E. T. Newton, having seen specimens from the Heathfield 

 boring, remarked on the difficulty of distinguishing between the 

 Wealden and the Purbeck beds ; but, judging from the few fossils 

 identifiable, he thought that Mr. Dawson was correct in ascribing 

 the beds met with at a depth of 353 feet to the Purbeck Series. 

 He also spoke of the high pressure at which the gas escaped from 

 the pipe, when the boring was visited by him about a fortnight 

 before the reading of these papers. 



Mr. C. E. Masteeman" thanked the Fellows for their appreciation 

 of his attempt to demonstrate the suitability of the gas for lighting 

 by incandescent mantles. He explained the nature of the burners 

 used, and said that he hoped shortly to be able to perfect the 

 apparatus still further. 



The Peesident and Dr. Isaac Robeets also spoke. 



Mr. Dawson said that the absence of the higher hydrocarbons in 

 Dr. Hewitt's analysis could not be reconciled with the normal 

 appearance of the gas, which could not be distinguished from the 

 appearance of ordinary coal-gas, and burnt with a bright yellow 

 flame, as might be seen from the sample now shown on the table. 

 Assuming both analyses to be correct, then the gas must vary 

 very considerably. Although variation had been noticed in the 

 North American natural gas, it had scarcely been to this extent. 

 The analyses of the lignite yielded results similar to those of most 

 lignites. The bands of lignite at the particular horizon from which 

 the analysed sample was taken were thin, and mixed with shale. 

 Thicker beds (about 2 feet) had been met with at Waldron, but no 

 gas had been discovered in them. He considered that the gas was 

 probably derived from the underlying petroleum-bearing strata. 



He wished to express his thanks to Mr, E. T. Newton, for the 

 identification of the Purbeck fossils ; to Messrs. Le Grand & 

 Sutcliffe, Mr. C. 0. Blaber, C.E., and Mr. John Lewis, C.E., for 

 kindly supplying details and plans of borings ; and to Mr. S. A. 

 Woodhead, B.Sc, for his analysis. 



Dr. Hewitt said, in reply to Mr. Dawson, the fact might be 

 mentioned that vegetable matter, when buried, from the time of its 

 death and through all stages until its final conversion into coal or 

 anthracite, continuously gives off methane; this is shown in the 

 occurrence of marsh-gas and of firedamp. Hence there is nothing 

 absurd in the supposition that the gas actually arose from the- 

 clay-bed impregnated with vegetable matter, the analysis of a 

 sample of which had been given. A natural gas having the 

 composition given in the analysis might equally as well have 

 arisen from a known bed containing organic matter as from a 

 hypothetical petroleum-bearing deposit. 



