Intelligence and Miscellaneous Articles. 387. 



southern part of the island, and layers of volcanic dust occur in it 

 at various horizons. There is everywhere a passage from the more 

 siliceous to the more calcareous earths. 



Prom the palaeontological and lithological evidence the authors 

 conclude that the depth of water in which the Oceanic beds were 

 deposited varied between 1000 and 2500 fathoms. The micro- 

 scopical and chemical evidence shows that the Radiolarian earths are 

 similar to modern .Radiolarian ooze ; that the calcareo-siliceous earths 

 are similar to what is called by Prof. Haeckel "mixed Radiolarian 

 ooze"; that some of the Foraminiferal earths are comparable 

 to Olobigerina-ooze from 1000 fathoms, and that others greatly 

 resemble European Chalk ; and, finally, that the coloured clays 

 bear a strong resemblance to the so-called " red clays " of modern 

 oceanic areas. Hence the raised Oceanic deposits of Barbados seem 

 to present us with an epitome of the various kinds of deposits 

 which are found on the floors of warm seas at the present day. 

 Equivalent deposits are known in Trinidad and Jamaica ; and 

 it is inferred by the authors that the whole Central American and 

 Caribbean region was deeply submerged during the Pliocene period, 

 leaving free communication at that time between the Atlantic and 

 Pacific Oceans. 



An Appendix by Mr. W. Hill treats of the minute structure of 

 the Oceanic earths and limestones and of the Foraminiferal muds 

 and detrital earths ; and this is supplemented by a Eeport from 

 Miss Eaisin on the inorganic material of certain Barbados rocks. 



3. " ArclicBopneustes ahruptus, a new Genus and Species of 

 Echinoid from the Oceanic Series in Barbados." By J. "W. Gregory, 

 Esq., B.Sc, F.G.S. 



XLV. Intelligence and Miscellaneous Articles. 



ON THE INTENSITY OF THE RADIATION OF GAS UNDER THE 

 INFLUENCE OF THE ELECTRICAL DISCHARGE. PRELIMINARY 

 NOTICE BY K. ANGSTROM *. 



I. HPHE interesting phenomena which accompany electrical dis- 

 -*- charge through rarefied gases, although still for the most 

 part unexplained, have of late been repeatedly investigated both in 

 the optical and in the electrical direction. The quantitative relation 

 between the optical and the electrical phenomena has, however, been 

 but little studied. Now it is only by a more perfect knowledge of 

 this relationship that we may hope to understand and explain the 

 origin and the nature of the radiation which we observe in Geissler's 

 tubes, as also the part which electricity plays in those remarkable 

 phenomena. 



Calorimetrical researches on the development of heat in Geissler's 



* Tran sla ted from a separate impression commimicated by the Author. 



