Correspondence. 239 



the meantime to adhere to the opinion I formerly expressed ; since 

 I am constrained to believe that the above-mentioned paleeontologists 

 must have had opportunities of studying this Graptolite as good as 

 those enjoyed by Mr. Carruthers. 



Finally, I am sorry that anything I have said should have led 

 Mr. Carruthers to the belief that I wished in any way to dogmatize 

 as to there being a connexion between the capsules and the Grapto- 

 lites ; and I should have thought I had stated with sufficient plain- 

 ness that I considered that my views were as yet conjectural, and 

 that Mr. Carruthers' opinions might " ultimately be proved to be 

 correct." I am likewise sorry that I should need to recal to Mr. 

 Carruthers' recollection, that the existence of capsules, "vertically 

 compressed," does not rest simply upon my "ipse dixit;" but that 

 Professor Harkness had seen my specimcDS, and had come to the 

 same conclusions about them as I had. I am, Sir, etc., 



H. Alleyne Nicholson. 

 Edinburgh, April IZth, 1867. 



A WAVE OF VOLCANIC DISTURBANCE IN THE MEDITERRANEAN. 

 To the Editor of the Geological Magazine. 



Sib, — The accounts of Earthquakes, Volcanic Eruptions, etc., 

 which have reached us from the Mediterranean coasts and islands, 

 during the latter part of the past, and the earlier part of the present 

 year, have been so numerous that they lead me to suspect that they 

 are attributable to one common origin, and are the result of a 

 plutonic agent which convulses the whole Mediterranean. 



These disturbances seem to date from the eruption of the islands 

 at Santorino last year. Professor D. T. Ansted was the first to 

 point out the connection of this phenomenon with the eruptions of 

 petroleum, which soon after took place at the sides of Mount Etna. 

 Again, M. Mauget recently sent a paper to the Paris Academy of 

 Sciences, stating that last July the wells and springs of Naples 

 and the neighbourhood suddenly diminished their supply; whilst, 

 by the injection of carbonic acid from the fissures diverging from 

 Mount Vesuvius, the fish were poisoned. This year the earthquake 

 at Algiers has been succeeded by the eruption of a " geyser ;" i.e., a 

 column of steam, fifteen or twenty yards high, has burst forth from 

 an aperture three feet in diameter, near the sources of the Ain-Bada. 

 Earthquakes at Cephalonia and Malta I mentioned in my last letter. 

 A more fearful shock, killing thousands of persons, and submerging 

 great part of the land, has been felt at Mytelene, on March 6th. 

 This earthquake was even experienced as far as Constantinople and 

 Smyrna. A volcanic eruption has occurred very lately at Pantellaria, 

 between Sicily and Africa. Eecent telegrams announce an earth- 

 quake at Naples. The ship " Sidon" announced that on March 7th, 

 being seven miles off Mytilene, they experienced tAvo shocks of a 

 submarine earthquake. 



Now does it not seem that all these phenomena point to a great 

 wave of volcanic agency disturbing the Mediterranean, its coasts, 



