Scientific Tntelli^nce — Geolopt/ and Mineralogy. 205 



hollow sounds, such as would be produced by a lai-ge drum. On two 

 subsequent trials we heard nothing, so that perhaps the sand requires 

 to be settled and at rest for some space of time before the effect can be 

 produced. The inhabitants have a belief that the sounds are only 

 heard on Friday ; nor then, unless by the special permission of the 

 saint of Reg-Ruwan, who is interred close to the spot. The locality of 

 the sand is remarkable, as there is no other in the neighbourhood Reg- 

 Ruwan faces the south, butthe wind of Pur wan (bad i Purwan), which 

 blows strongly from the north for the greater part of the year, probably 

 deposits it by an eddy. Such is the violence of this wind, that all the 

 trees in the neighbourhood bend to the south; and the fields, after a 

 few years, require to be' re-cleared of the pebbles and stones which the 

 loss of soil lays bare. The mountains around are for the most part 

 compo£ed of granite, but at Reg-Ruwan we found sandstone, lime, 

 slate, and quartz. Near the strip of sand there is a strong echo; 

 and the same conformation of surface which occasions this is doubtless 

 connected with the sound of the moving sand. In a late number of 

 the Journal of the Asiatic Society of Calcutta, there is an extract of a 

 letter from Lieutenant Wellsted, of the Indian navy, in which he de- 

 scribes the sounding mountain in the Red Sea, which has also been 

 mentioned by Gray and Seetzen. There would appear, however, 

 to be some variation in the kind of sound produced in the two 

 places; but both are, I suppose, explained by the theory laid down by 

 Mr James Prinsep regarding Jubl Nakoos, who says that the effect is 

 there produced merely by '■' a reduplication of impulse, setting air in vi- 

 bration in a focus of echo.*' At all events, we have at Reg-Rewan ano- 

 ther example of the phenomenon to excite the curiosity of those inte- 

 rested in acoustics. Reg-Ruwan is seen from a great distance; and 

 the situation of the sand is so peculiar, that it might almost be ima- 

 gined the hill had been cut into two, and that it had gushed forth from 

 the opening as from a sand-bag; the probability, however, is, that it 

 lias been brought together by the wind. 



10. Fossil Fwaminifera inthe Green Sand of New Jersey (America.) 

 — Prof. J. W. Bailey has brought to light the interesting fact, that u 

 large portion of the calcareous rock defined by Prof. H. D. Rogers as 

 the third formation of the upper secondary, is made up, at the locali- 

 ties where he examined it, of great quantities of microscopic shells be- 

 longing to the foraminifera of D'Orbigny, which order includes those 

 multilocular shells which compose a large part of the calcareous sands, 

 &c. of Grignon and other localities in the tertiary deposits of Europe. 

 Since the minute multilocular shells above alluded to were discovered. 



