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SCIENCE-GOSSIP. 



GEOLOGY 





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CONDUCTED BY EDWARD A. MARTIN, F.G.S. 



To whom ail Notes, Articles and material relating to Geology. 



and intended for Science-Gossip, are, in the first instance, to 



be addressed at 69, Bensham Manor Road. Thornton Heath. 



New Officers of Geological Society. — We 

 note with much pleasure the election on February 

 18th of Mr. W. Whitaker, B.A., F.R.S., as Presi- 

 dent of the Geological Society of London. Mr. 

 Whitaker is chiefly known by his important Survey 

 Memoir on the "Geology of London," and his 

 election is a popular one. The two new Vice- 

 Presidents are Prcf. J. W.Judd,C.B.,LL.D.,F.R.S., 

 and the Rev. H. H. Winwood, M.A., whilst Prof. 

 T. G Bonney, D.Sc, LL.D., F.R.S., and Mr. 

 J. J. H. Teall, M.A., F.R.S., still retain office as 

 Vice-Presidents. Mr. J. E. Marr, M.A., F.R.S., 

 retires from one of the secretaryships, and is 

 replaced by Mr. W. W. Watts, M.A. 



Igneous Fragments in Bagshot Beds. — At 

 the meeting of the Geological Society of London 

 on January 19th Mr. H. W. Monckton read a 

 paper " On some Gravels of the Bagshot District." 

 The subject is in continuation of former papers 

 published in the " Quarterly Journal " 1892 (p. 29) 

 and 1893 (p. 30S). In discussing the paper Mr. 

 W. H. Shrubsole mentioned that in about 187S he 

 had found many irregular fragments of igneous 

 rocks imbedded in the upper part of the Lower 

 Bagshot Sand at Mill Hill, Sheppey. They were 

 judged to have been conveyed from Scandinavia, 

 and probably ice was the transporting agent. 



On Humus. — In the January number (ante 

 p. 242) there is a note anent humus, which, as 

 defined by Bertholet and Andre, is that portion of 

 the remains of vegetation which resists the action 

 of the air and lower organisms and remains as an 

 insoluble residue in the soil, supplying the roots of 

 the higher plants with nitrogen, sulphur, phos- 

 phorus, alkalies, etc. It contains about 34 per 

 cent, organic matter. In some humid soils the 

 amount of humus reaches 5 per cent, as against 

 075 per cent, yielded by arid soils. Pasture 

 and some forest soils are much richer in it than 

 are arable soils. For purposes of investigation the 

 air-dried soil is placed on a filter and repeatedly 

 saturated with water ; the filtrate, which is usually 

 acid in reaction, is evaporated to a small bulk, 

 and the pale-brown, syrupy liquid is filtered and 

 evaporated to dryness. The residue is treated with 

 water when the ulmic, geic and humic acids, com- 

 bined with bases, remain undissolved, whilst crenic 

 and apocrenic acids, as ammonia salts, are dissolved. 

 According to Eggerton, however, humic and ulmic 

 acids do not naturally occur in peat and similar 

 products, but are merely artificial laboratory pro- 

 ducts, and the existence of humine and ulmine is 

 very doubtful, while crenic and creno-hydrochloric 

 acids doubtless do exist as independent bodies. It 

 is known that the decay of vegetable matter is 

 brought about by attacks first of bacteria, when 

 it becomes acid, and when these decay the ammonia 

 produced neutralises the acid ; and then, secondly, 



moulds appear to grow in the neutral medium. 

 Finally, both bacteria and moulds develop together. 

 Soils which are rich in humus are looser ; they 

 have a great power of taking up water and of 

 "absorbing" and retaining the alkalies dissolved 

 therein. It is supposed that the moulds, not the 

 bacteria, take an active part in the mineralization 

 of organic nitrogen. No doubt the amount of com- 

 bined nitrogen is much increased by these agents. 

 What is more wonderful is that the plant responds 

 to the circumstances ; it spreads out its roots in all 

 directions in order to make the most of the humus, 

 which is very nutritious. It is extremely doubtful 

 if the humic acids (if indeed such exist at all, at 

 least in the free state) exert much influence in the 

 disintegration of rocks, even of soft, porous lime- 

 stone. Excessively comminuted as is the soil when 

 it becomes deficient in water, the accumulation 

 of humus is retarded ; but where, on the other 

 hand, the soil is permeable only to a small depth 

 by water this accumulation is increased. The 

 penetration of limestone by the fine roots of plants 

 may help to disintegrate it, but it is much more 

 probable that carbonated rain-water is the most 

 potent agent in the weathering thereof and the 

 formation of holes like inverted cones. — {Dr.) P. 

 Q. Keegaii, Patterdale , Westmoreland. 



Indiana Petroleum. — A mass of interesting 

 geological information in regard to the natural 

 resources of Indiana is contained in the report 

 recently published by W. S. Blatchley, the State 

 Geologist . The petroleum industry started here only 

 in 1891, andinfiveyearstheoutputreached4,659,ooo 

 barrels. In 1896 no less then 1,180 new borings 

 were put down in search of oil, and of these 158 

 were dry. The producing territory comprises 

 about 400 square miles. The average age of an 

 oil-well is said to be about five years, and a 

 number of the first wells put down have already 

 been abandoned. Surface indications of oil seem 

 to be quite unreliable, but where oil does occur, it is 

 met with at depths varying from 700 to 1,500 feet 

 below the surface. 



Natural Gas. — In Indiana there is an area of 

 2,500 square miles over which, roughly speaking, 

 natural gas is obtainable. No other State in the 

 Union has so large a productive area. There is 

 evidence to show, however, that in much of this 

 area the supply of gas is failing, although in an 

 area of some 400 square miles in the heart of the 

 field there are few signs of water or other influ- 

 ences tending to diminish the supply of the gas. 

 We note that some manufacturing establishments 

 are said to consume half-a-million or more feet 

 a day. One can scarcely wonder that the speedy 

 exhaustion of the supply is considered a cer- 

 tainty in the near future. By careful consumption 

 a decade may be passed before extinction is reached. 



Foreign Boulders in the Chalk. — In answer 

 to your note in Science-Gossip on foreign stones 

 in chalk, I have a piece of granite that I found on 

 the beach about a mile from Margate ; although 

 not in situ in the chalk, but loose, I have no doubt 

 that it came from the chalk. It is a pinkish colour 

 with large felspar crystals, and is unlike any 

 granite that I know. There are no buildings 

 anywhere near built of granite, whence it might 

 have come, and there are not any in Margate with 

 granite like this. It has not been rolled much, the 

 angles being too sharp. I have worked the cliffs of 

 the Isle of Thanet for some years now, but have 

 never seen anything in the way of granite before. — 

 Thos. Edwards, CliftonviUe, Equity Road, Leicester. 



