230 Intelligence and Miscellaneous Articles. 



A letter was afterwards read, addressed to Dr.Buckland, P.G.S. 

 by the Rev. John Gunn, and dated Dec. 21st, 1839. 



This letter was accompanied by three paramoudras from the chalk 

 near Norwich ; and they had been selected by Mr. Gunn on account 

 of one of them presenting a tuberculated exterior, a character which 

 he states a paramoudra commonly assumes when it is in contact 

 with horizontal lines of nodular flints ; and the other two had been 

 chosen because Belemnites and shells are imbedded in their sub- 

 stance. The letter contains some observations on the irregularities in 

 the surface of the Norfolk chalk, and on the pipes or sand galls by 

 which it is penetrated. With reference to these tubular hollows, 

 Mr. Gunn refers to Mr. Lyell's description of them, read at the 

 meeting of the British Association at Birmingham, but he calls at- 

 tention to their being constantly filled in the district examined by 

 himself, with sand, gravel, or crag, to the total exclusion of all ma- 

 terials belonging to the strata between the chalk and the crag ; and 

 he therefore infers, that the sand galls were not eroded during the 

 eocene period, but that during that long period the Norfolk chalk 

 was denudated. 



The letter was also accompanied by some specimens from the 

 boulders contained in the diluvial (drift) strata of Norfolk and Suf- 

 folk. Mr. Gunn is of opinion that these masses of rock indicate 

 what were the strata that formed the shore against which the (so- 

 called) diluvial waves washed ; and that the masses were borne out 

 to sea in a similar manner to the portions of cliff now annually de- 

 stroyed by the waves. If the bottom of the present sea were raised, 

 he says it would present features analogous to those of the crag and 

 diluvial formations of Norfolk and Suffolk. 





M 



XXXIV. Intelligence and Miscellaneous Articles. 



PHENOMENA OF CALEFACTION. 



BOUTIGNY has read a paper before the Academy of Sci- 

 • ences on Calefaction, by which term he designates the singu- 

 lar phenomenon presented by water when drops of it are thrown 

 upon a very hot metallic surface. 



It has generally been supposed that this effect is produced only 

 at a very high temperature, but M. Boutigny finds that it occurs in 

 a lead crucible, and consequently below 612° Fahrenheit. 



M. Boutigny has observed also that aether gradually dropped into a 

 platina crucible nearly red-hot, calefies as well as water, that is to 

 say, the mass becomes round, without the occurrence of any appear- 

 ance of ebullition, is afterwards rapidly agitated, and does not 

 seem to wet the crucible. The quantity, however, goes on dimi- 

 nishing, but much less rapidly than if the vessel were cold. Du- 

 ring this slow evaporation, a very irritating vapour arises, which 

 does not at all resemble that of sether, but which in smell greatly 

 resembles aldehyde, and of this the author supposes it to consist ; 

 the presence of air appears to be necessary to the production of this 

 vapour. The commissioner to whom M. Boutigny's paper was 



