434 



*' fame with them in every refpeft. A particular diflrlct of Etna, 

 " comprehending the Cyclopian Iflands, the country round La Frezza, 

 " and tiie caftle of Jaci, is decidedly of this defcription." * 



Here we have the moft refpectable authority for faying, what Mr. 

 Brydone flippantly calls currents of lava, never flowed from any volca- 

 no ; of courfe, all his calculations vanifh in air. 



Previous to entering into any difcuflion of Dr. Hutton's fyftem, lu- 

 dicroufly, yet properly enough fl;yled The Plutonic Theory, I will 

 give a fhort epitome of it, that fuch readers as are not already ac- 

 quainted with it, may be aware how much it is expected they fliall 

 believe. 



Dr. Hutton aflirts, that the materials of which the furface of 

 this world is compofed, loofe and folid, are perpetually decaying, or 

 decompofing, and in that ftate are waflied away by the rivers 

 into the fea, thence by the tides and currents into the unfathoma- 

 ble regions of the ocean : 



That our furface, thus perpetually diminifliing, in length of time is 

 completely carried off, and depofited in the form of horizontal ftrata 

 at the bottom of the fea : 



That there fires are by fome myfterious operation kindled, by which 

 the loofe materials of thefe fl:rata are fufed and confolidated into the 

 hardefl; rocks, as marble, and every other fpecies of flone, except gra- 

 nite, of which the Doctor has fome doubt :t 



That 



*■ These were the places, together with Paterno and La Mothe, which I selected 

 as the subject of my observations intended for the late Mr. Dolomieu, 



t Dr. Beddoes gets over Dr. Hullon's difficulties (whatever they were) by aflerting ba- 

 salt (with him unqueftionable lava) and ^ran:V« to pass into each other; an assertion I /hould 

 not have minded, had he not drawn his proof horn my country, confidering the whjnjloiie 

 of the Fairhead pillars as an approximation to gianite. 



Our country affords many varieties of basalt, that of Fairhead is somewhat more granular" 

 and of a lighter colour than the fine blue Giant's Causeway basalt, but it is obviously pure 

 basalt ; nor did I ever there, or any where with us, observe the trace of a passage of ba- 

 salt into granite. In truth we have very little granite, and what I have met with was invari- 

 ably of the red species. 



