Natural History. 24l 



it was again produced. It appeared to me like that of a hum- 

 ming-top, and increased and diminished, like the sounds of an 

 iEolian harp. To convince myself of the truth of my conjecture, 

 I crawled with the utmost difficulty up to the highest rocks, and 

 then allowed myself to slide as rapidly as possible, endeavouring 

 with my feet and hands to put the sand in motion. The effect 

 thus produced was so great, and the sand rolling beneath me 

 caused a sound so intense, that the earth appeared to tremble, 

 and I should have been dismayed if the cause had been unknown 

 to me. 



"But how can this motion of the sand produce so intense an 

 effect, and one observed, I believe, no where else? Does the 

 rolling layer of sand act like a bow, which by its friction on a 

 plate of glass will cause the powder spread over it to tremble 

 and acquire determinate figures ? Does the fixed and adhering 

 layer of sand perform the part of the glass plate, and the neigh- 

 bouring rocks that of the resounding body? These are questions 

 which the natural philosopher must decide. — Ann. de Chimie^ 

 xxxiii. 435. 



2. Italian Cavern containing Bones. — With the exception of a 

 small cavern in the island of Elba, none containing bones like 

 those which have become so celebrated in England and Germany, 

 had been discovered in Italy. Lately, however. Professor Gae- 

 tano Savi has discovered one in one of the mountains which sur- 

 round the gulf of Spezia, opposite to Cassana, a village not far 

 removed from Casale. Many of the bones contained in this 

 cavern belong to the same species of bear of which the bones 

 have been found in such large quantities in the caverns of northern 

 Europe. Other bones belong to the ruminantia, others to herbi- 

 vorous animals, and apparently to the stag. All these bones are 

 broken and incrusted. — Giornale deFisica, ix. 154. 



3. Crystallization of Asbestus. — M. Hess, of Dorpat, has ex- 

 amined a mineral from the village of Pitkaranda, near the lake 

 Ladoga, and has determined it to be a crystallized variety of 

 asbestus. He describes its primitive form as an oblique rhom- 

 boidal prism, of 84° 36', of which the base is inclined on the 

 obtuse sides, with angles of 104°. Its analysis gave him, silica, 

 45.57 ; protoxide of iron, 19.73 ; alumine, 3 ; lime, 4.4 ; mag- 

 nesia, 23.4 ; water, 2. — Archives des S. Nat. v. 321. 



4. Dense Fogs. — ^There have been remarked at different times in 

 the winter season such dense fogs as to occasion serious acci- 

 dents fi-om their interference with distinct vision. These are 

 observed in and about large towns only, and are supposed by 

 M. Defranc to originate from the stagnation of the smoke and 

 vapours generated in such situations. On certain calm winter 

 days, it may be observed that the smoke, on leaving the chimneys, 



JAN.— MARCH, 1827. R 



