128 PEOCEEMNGS OP THE GEOLOGICAL SOCIETY. [June 23, 



the ordinary pores of recent lava. The most compact mass is near 

 the sides of the dyke. Towards the interior of the dyke, this com- 

 pact crust is lined by a small zone, finely porous, which soon gives 

 place to the homogeneous central stone, quite free from pores, ex- 

 cepting in the before-said highly porous zone iu the axis. The 

 magnetic power of this dyke is extraordinary ; the needle, when 

 approached, turns immediately at a right angle to the surface of the 

 dyke's sides. 



The importance of this phaenomenon on this part of the mountain 

 as respects the history of Mount Etna, is obvious. There cannot be 

 any doubt that the outburst of this eruptive matter, becoming 

 immediately a lava-current on that side where the inclination of 

 the soil favoured its descent, took place when the whole system of 

 those alternating layers of tufa, conglomerates, and lava, now called 

 Etna, which the dyke has cut through, existed almost in its actual 

 position. The considerable extension of the bed in fig. 11 throws 

 much light on the manner by which a great part, perhaps the 

 greatest part, of what we have called the older Etna may have been 

 built up by successive eruptions out of longitudinal vents, under the 

 synchronous influence of a gradual slow upheaving of the whole 

 system. The direction N.N.W. and S.S.E. is the prevailing one 

 with the dykes round Etna, as well as in the interior of the Yal di 

 Bove. But it is remarkable that this direction is also the parallel 

 of the longitudinal axis of the older Etna (figs. 8 and 9, a, h), such 

 as the mountain was before the catastrophe which was followed 

 by the subsidence of what we now call the ^' Val di Bove." The 

 most modern consequence of this direction, by which, in the earliest 

 period of the volcanic eruptions, were traced the first lines of what 

 became so immense a construction in our modern epoch of lava- 

 formation, is the rent across the Piano del Lago on the top of the 

 old Mount Etna ! 



But I believe it is now time to return from this long excursion 

 round Etna, to which I felt myself irresistibly invited by your 

 questions. My election, too, as a Member of the London Geological 

 Society incited me, and most agreeably too, to prove to you, by this 

 communication, and to the Society also, how much I feel myself 

 honoured by the honorary title of Eoreign Member lately given me. 



2. On the Lacusteine or Karewah Deposits of Kashmie. By 

 H. H. Godwin- Austen, Lieut. H.M. 24th Regt., Kashmir Survey. 



[The publication of this paper is unavoidably postponed.] 



