16 



1 in. thick, diameter of innei' ball 3 in., diameter of outer shell 5 in. 8. Fine 

 specimen of native sulphur, with geodi lined with crystals. 7. Nepheline, 

 a silicate of alumina and soda from the centre of lava from Monte Somma, 

 with geode lined with beautiful crystals of glassy felspar. 14. Augitic and 

 leucitic lava from the eruption of 1631 ; upper surface covered with 

 atacamite — native copper. Lavas representing eruptions of various dates. 

 Ancient rocks were shown corresponding in composition with the lavas, 

 but altered by pressure and the absorption of other mineral matter. Mr. 

 Hardcastle's explanation of the projection and formation of volcanic bombs, 

 lapilli, &c., was the same in substance as the following passage from 

 Professor Judd's "Volcanoes" (London, 1881), pp. 69-70: — "Various 

 names have been given by geologists to the fragments ejected from volcanic 

 vents, which, as we have seen, differ greatly in their dimensions and other 

 characters. Sometimes masses of more or less fluid lava are flung bodily 

 to a great height in the atmosphere. During their rise and fall these 

 masses are caused to rotate, and in consequence assume a globular or 

 spheroidal form. The water imprisoned in these masses during their 

 passage through the atmosphere tends to expand into steam, and they 

 become more or less completely distended with bubbles. Such masses, 

 which sometimes assume very regular and striking forms, are known as 

 ' volcanic bombs.' Many volcanic bombs have a solid nucleus of refractory 

 materials. The large, rough, angular, cindery looking fragments are termed 

 .scoriae. When reduced to the dimensions of a marble or pea they are 

 usually called by the Italian name of 'lapilli.' The still finer materials 

 are known as volcanic sand and dust." And the following passage from 

 Professor Phillips's " Vesuvius, 1869 : " — " The showers of lapilli, ashe.s, and 

 dust, which make so large a portion of the mass of Vesuvius, may be 

 regarded as disintegrated lava — crystalline grains or dust separated by the 

 deveilent force of the explosion — the force of steam — pervading some parts, 

 perhaps every part of the fluid mass." Another interesting exhibit was 

 that brought by John T. Beer, F.RS.Lit., who showed bones and 

 teeth of the hyena, cave bear, woolly rhinoceros, horse, &c., and a specimen 

 of breccia from the Cresswell Caves, near Welbeck. Some of the bones 

 showed the marks of having been crushed by the hyena's teeth. He also 

 showed teeth of the mammoth and of sharks from the marl cliffs of 

 Whitstable, Kent, and a number of small marine shells from a boring made 

 to a depth of fifty feet beneath the Goodwin Sands. Dr. Crowther, of 

 Wakefield, exhibited specimens of two crabs— Galathea squamifera and G. 

 strigosa — from Cornwall, which had been preserved in a manner that 

 retained the natural colours of the animals. F. W. Branson, F.C.S., 

 showed some interesting abnormal formations of the sweet orange, in which 

 the seeds were of the same fleshy consistence as the remainder of the 

 fruit. J. W. Addyman, B.A., showed some soundings from the North 

 Atlantic, from a depth of 2,150 fathoms, and made in north latitude 34 deg. 

 23 min. 30 sec, and west longitude 14 deg. 13 min. sec, and a series of 

 mounted slides of the forms contained. 



