306 ANNUAL OF SCIENTIFIC DISCOVERY. 



brooks spread in different directions. These ponds harbor the same, 

 little Cyprinodonts which rise in the water of the artesian wells, by 

 which I conclude that a subterranean connection exists between the 

 ponds and the wells. Probably they visit those ponds periodically 

 perhaps to spawn ; this would explain why their eyes, and their forma- 

 tion in general, show nothing abnormal. 



DISCOVERY OF EMERY IN THE UNITED STATES. 



It has been remarked that " a good mine of emery is worth more 

 to a manufacturing people than many mines of gold." At a recent 

 meeting of the Boston Society of Natural History, Dr. C. T. Jackson 

 announced the discovery of an apparently inexhaustible mine of 

 emery in the town of Chester, Western Massachusetts, on the line of 

 the Springfield and Albany railroad. For some time the existence of 

 magnetic iron-ore was recognized in this locality, and the deposit 

 worked to some extent, but on examination, Dr. 'Jackson found that 

 the ore in question was in great part pure emery. The principal bed 

 is in some places ten feet in thickness, and has been traced some four 

 miles. In appearance it resembles the emery of Naxos and practical 

 tests of it in grinding sword-blades at the Ames Manufacturing Co. 

 at Chicopee, are said to be every way satisfactory. 



MICROSCOPICAL STRUCTURE OF METEORITES. 



Mr. H. C. Sorby, eminent for his application of the principles of 

 physics in explaining geological phenomena, and his study of the 

 microscopical structure of crystals, has turned his attention to the 

 structure of meteorites. In a paper recently presented to the Royal 

 Society he says that, in the first place, it is important to remark that 

 the olivine of meteorites contains most excellent "glass cavities" 

 similar to those in the olivine of lavas, thus proving that the material 

 was at one time in a state of igneous fusion. The olivine also con- 

 tains "gas cavities" like those so common in volcanic minerals, thus 

 indicating the presence of some gas or vapor. To see these cavities 

 distinctly, a carefully prepared thin section and a magnifying power 

 of several hundreds are required. The vitreous substance found in 

 the cavities is also to be met with outside and amongst the crystals, 

 in such a manner as to show that it is the uncrystalline residue of the 

 material in which they were formed. It is of a claret or brownish 

 color, and possesses the characteristic structure and optical properties 

 of artificial glasses. Some isolated portions- of meteorites have also a 

 .structure very similar to that of stony lavas, where the shape and mu- 

 tual relations of the crystals to each other proved that they were 

 formed in vita on solidification. A structure is also found so remark- 

 ably like that of consolidated volcanic ashes as to be taken for it. It 

 would appear that after the material of the meteorites was melted, 

 a considerable portion was broken up into small fragments, subse- 

 quently collected together, and more or less consolidated by mechan- 

 ical and chemical means, amongst which must be classed a segrega- 

 tion of iron either in the metallic state or in combination with other 

 sub.-'tnnces. "There are," says Mr. Sorby, "certain peculiarities 

 in physical structure which connect meteorites with volcanic rocks, and 

 at the same lime, others in which they diil'er most characteristically, 



