218 



SCIENCE-GOSSIP. 



literature on the subject grows apace. This latest 

 addition marks a distinct advance, and it should 

 therefore be read by all entomologists who are 

 interested in the microscopic details of structure 

 and the affinities of insects as determined by the 

 structure of their organs. 



A Finishing Cement. — In reply to T. W. W. 

 Sheffield and others, a good cement varnish may 

 be made by dissolving shellac in alcohol, and 

 colouring it with aniline blue, red, etc. 



A Cheap Slide Series.— Mr. F. Smith, of 

 15, Cloudesley Place, Islington, has sent us his list 

 of micro-objects, together with a type series of 

 slides. The objects are well mounted and very 

 moderately priced. 



Fossils in Amber. — More than 200 kinds of 

 extinct life, microscopic and otherwise, including 

 insects, plants, shells, fruit, reptiles, etc., have 

 been found in amber. In an English collection, 

 which is valued at ^100,000, there is entombed 

 a perfect lizard eight inches long. 



The Microscope and Geology.- — "Microscopi- 

 cal Light in Geological Darkness " formed the text 

 of Professor E. W. Claypole's presidential address 

 at the last meeting of the American Microscopical 

 Society, After making out a strong case for the 

 aid furnished by the microscope in geological study 

 he proceeded to instance the remarkable discovery 

 of the existence of innumerable inclusions of liquid 

 carbonic acid in the rocks which was made by 

 Dr. H. C. Sorby, of Sheffield. The investigations 

 that followed on this discovery have shown that 

 these bubbles of liquid gas are present "by myriads 

 and by millions, and not in gems only, but in 

 other crystalline minerals. In size they range 

 between the one-thousandth and fifty-thousandth 

 part of an inch, but they are so multitudinous as 

 often to impart a white tint to the crystal, and 

 many specimens of milky quartz owe their white- 

 ness solely to the presence of these innumerable 

 bubbles. In some of the Cornish granites the 

 cavities make five per cent of the volume, and 

 yield four pounds of the liquid to every ton of the 

 rock." Mr. J. C. Ward is quoted as saying that 

 more than a thousand millions of them might be 

 contained easily within a cubic inch of quartz. 



Origin of Coal. — Professor Claypole used this 

 fact to discuss the problem of the origin of coal. 

 Coal is derived from plants which have extracted 

 carbon from the carbonic acid of the atmosphere. 

 Whence was that carbonic acid derived? It has 

 been said that it was one of the original constituents 

 of the atmosphere; but Professor Claypole adduces 

 many reasons to show that all the carbonic acid 

 represented in the coal beds could never have been 

 in the atmosphere at one time. How then and 

 whence were the successive supplies introduced ? 

 The experiments of Dr. Sorby and of Professor 

 Tilden have shown that from 1-3 to 17-8 of the 

 bulk of most rocks consists of gases of which 

 hydrogen and carbonic acid are the most abundant. 

 Professor Claypole suggests that the carbonic acid 

 used up in the formation of coal has been derived 

 from the breaking up of the minute reservoirs of 

 C0 2 which were contained in the immense volumes 

 of the primary rocks that have been undergoing 

 degradation from the commencement of the geologi- 

 cal history of the world. Professor Claypole makes 

 a brief calculation to show the amount contained in 

 these wasted rocks is more than enough to account 

 for all the coal known to exist. 



GEOLOGY 



•""gj^gSfeJ^P?,; 



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



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

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

 to be addressed, at 6q, Bensham Manor Road, Thornton Heath. 



Geological Society of London. — The Geo- 

 logical Society re-commenced its meetings on 

 November 9th, when papers were read on the 

 " Palaeozoic Radiolarian Rocks of New South 

 Wales," by Prof. Edgeworth David, E. F. Pittman 

 and Dr. G. J. Hinde. The first evidence of the 

 presence of Radiolaria in the rocks of New South 

 Wales was obtained by Prof. David in 1895, as the 

 result of a microscopic examination of some red 

 jaspers from different areas. The three chief areas 

 of radiolarian rocks in New South Wales are 

 Bingara, Barraba and Tamworth, situated in the 

 New England District, between 1S0 and 270 miles 

 to the north of Sydney. The fourth area of 

 radiolarian rocks is at the well-known Jenolan 

 Caves, about sixty-seven miles due west of Sydney 

 and about 200 miles south-by-west of Tamworth, 

 It is probable, according to present knowledge, 

 that the Jenolan rocks may be on a somewhat 

 different, perhaps lower, horizon than those of the 

 northern district. 



Radiolarian Rocks at Tamworth, N.S.W. — 

 It is at Tamworth that the radiolarian rocks are 

 developed on a grand scale ; their measured thick- 

 ness, after allowing for an immense fault, amounting 

 to 9,267 feet, and neither upward nor downward limit 

 is shown. The rocks consist of jointed claystones, 

 black cherts, lenticular siliceous radiolarian lime- 

 stones and coral-limestones. Numerous beds of 

 submarine tuff also occur. The claystones are 

 largely formed of Radiolaria. In certain beds of 

 the claystones, and in some .of the tuffs as well, 

 impressions of Lepidodendron aitstrale are not un- 

 common, and beds of radiolarian limestone occur 

 in close proximity to the beds with these plant- 

 remains, and Radiolaria, moreover, abound even in 

 the same rock with the Lepidodendron impressions. 

 The opinion is that the Radiolaria were deposited 

 in clear sea-water, which, though sufficiently far 

 from land to be beyond the reach of any but the 

 finest sediment, was nevertheless probably not of 

 very considerable depth. 



Devonian Radiolaria of Australia. — In re- 

 porting on the Radiolaria in the Devonian rocks of 

 New South W T ales, Dr. G. J. Hinde found that in 

 the chert and jasper rocks of the Jenolan, Bingara 

 and Tamworth districts, the Radiolaria were for the 

 most part in the condition of casts filled with 

 chalcedonic silica and without structure, so that 

 their generic characters could not be determined. 

 However, in the siliceous limestones and in the 

 volcanic tuffs, the Radiolaria were imbedded and 

 infiltrated with calcite, and by careful etching of 

 thin sections of the rock, the lime was eliminated 

 and the organisms were shown very distinctly. 

 The rock then appeared as a confused mass of 

 entire and fragmentary Radiolaria and minute 



