54 KEPORT — 1867. 



While so much has beeu done in this respect by chemists and geologists abroad, 

 we are but little further forward than when the great outlines of the subject were 

 sketched long ago by the eaiiy leaders in the science. The same vague names, the 

 same confused and defective arrangement, the same absence of careful chemical 

 and miueraiogical analysis, so excusable in the infaucj' of the science, still disfigure 

 cm- geological writings and even the best of our geological collections. Field- 

 geologists must be content to bear their share of tlie blame ; yet it is not from 

 their hands that the needed reform is mainly to be looked for. They can do but 

 little till chemistry comes to their aid with information regarding the composition 

 of the rocks which they investigate, and the extent to which the nomenclature 

 adopted in other countries can be applied in their own. Siu'ely the time must 

 come ere long when it -wdll be deemed a task worthy of years of long and patient 

 research to work out the natm'e and history of the volcanic rocks of this country. 

 Such a task will not be the work of a single observer. It will require the labour 

 of the geologist, skilled to glean the data that can only be gathered in the field, 

 and of the chemist who, aided and guided by these observations, shall seek to 

 determine the composition of the diflerent igneous rocks, and the relation which, 

 in this respect, they bear to the rocks of other regions, and to tlie products of 

 modern volcanoes. But whether distant or near, the day will doubtless arrive 

 when we shall be able to connect into one story, as far at least as our fragmentary 

 records j[will permit, the narrative of the varied volcanic eruptions which from 

 early geological times have taken place in the British Islands, and to link that 

 chronicle with the long history of volcanic action over the globe. 



The passage of Schists into Granite in the Island of Corsica. 

 By D. T. AifSTED, M.A., F.R.S. 



The object of this communication was to advocate the view that granite is a 

 metamoi-phic rock, and not in any sense primitive or the nucleus of the earth. A 

 section was described, the result of observations recently made, taken on the side 

 of a road recently made between He Eousse and S. Florent, on the north-western 

 side of the island. The section presented unniistakeable and numerous alterna- 

 tions of compact, well-crystallized, whitish-grey granite, with argillaceous rock, 

 schists, grits, and rotten granite. The dip of the various beds varies from 30° to 

 10°, diminishing towards the north ; the thickness of tlic beds is often several yards, 

 but not very great. There is much granite near, towards the interior of the coim- 

 try, and stratified rocks near the coast. The general inference of the author fi'om 

 this section was, that granites are not erupted but metamorphic rocks. 



On the Lagoons of Corsica. By D. T. Ansied, M.A., F.R.S. 



The eastern coast of Corsica, though now the most malarious district in the 

 Mediterranean, was inhabited and healtliy 2000 years ago ; and there is good his- 

 torical e'vidence that it continued healthy till the end of the fifteenth century. 

 Remains of two cities are still to be traced on these plains, which are now abso- 

 lutely deserted. Each town was situated at the southern extremity of a large 

 existing lagoon, near a principal river, provided in each case with a delta. Beyond 

 each river, to the north, are numerous small torrents, originally entering the sea, 

 but now feeding the lagoons, which have been formed by the sands of the delta 

 drifted northwards from one river delta to the next beyond, owing to the prevalent 

 winds. The drainage of the torrents is received into and supplies the lagoons. 

 During summer there is no water brought down, and a sand-bar has accumulated 

 until it has become a bank. In winter, the waters brought down are driven 

 towards the northern and open end to escape, but they leave behind a large quan- 

 tity of organic matter which during the subsequent heats of summer rots, and 

 becomes converted into miasma. So long as the communication was open from 

 the torrents to the sea the coast was healthy, but so soon as the lagoon was 

 formed the malaria set in. 



The largest of the lagoons is that of Biguglia, extending from the delta of the 

 Golo nearly eight miles towards the north. Its greatest width is 3000 yards, 

 diminishing first to 2000 for a long distance, and then to 1000. About a mile 



