British Association. 465 



The thermometer seems to act in a similar manner with spirits 

 under proof; thus, with spirits ten per cent, under proof, mixed 

 with water as above, it will rise about 8^,°, and one degree less for 

 every 10 per cent, under proof, until we get to 45° under proof; 

 after which, although a rise does take place, the indications do not 

 seem to be so regular. 



When the spirits are mixed with sugar increasing the specific 

 gravity so as to falsify the hydrometer 20 or 30 per cent, or more, 

 the indications of the thermometer are precisely the same, making 

 allowance for the slight difference in volume caused by the mixture 

 of sugar. 



Jf the mixtures be made at higher temperatures, the indications 

 of the thermometer are proportionally a lesser number of degrees, 

 according to the temperature ; I think when between 70° and 80° 

 nearly 2 degrees less, but the progressions appear to go on regularly 

 as before. 



I do not, however, presume to give the above as accurate results, 

 but merely to state that the thermometer appears to indicate a regular 

 progression according to the strength of the spirits, and the tempe- 

 ratures at which they may be mixed with the water. 



My only desire at present is to draw the attention of men of 

 science to the subject, who may discover some mode of application 

 which may render it available, and perhaps accurate, in ascertaining 

 the qualities of spirits or acids. 



Abstract of a Paper read before the 3Iembers of the JBritish 

 Association^ at Bristol, August 20, 1836, entitled^ *' On some 

 Fallacies involved in the Kesults relating to the comparative 

 Age of Tertiary Deposits obtained from the Application of 

 the Test recently introduced by Mr. Lyell and M, Deslmyes." 

 By Edward Charlesworth, Esq., F. G. S. 



During the author's investigation of the fossiliferous strata above 

 the London clay in Suffolk and Norfolk, some facts have come 

 under his observation, which appear to him to point out sources of 

 error to a considerable extent in the application of the test recently 

 proposed by M. Deshayes and Mr. Lyell, and which is now so 

 generally made use of in the classification of tertiary formations. 



The crag has been referred by Mr. Lyell to his older jdiocene 

 period, on the authority of Deshayes, who identified among the 

 fossil testacea of that deposit 40 per cent, with the existing species. 

 The correctness of this result has been called in question by other 

 eminent conch ologists, particularly by Dr. Beck, of Copenhagen, 

 who has examined the crag fossils in the author's collection, and 

 considers that the whole of them are extinct. In this opinion Dr. 

 Beck is supported by Mr. G. B. Sowerby, who states, that he has 

 only met with two or three crag shells, which may, perhaps, be 

 identified with existing species. Professor Agassiz has inspected an 

 extensive series of ichthyological remains, collected from the crag by 

 the author, and pronounces them all to belong to extinct genera or 

 species; while a precisely similar result has attended Dr. Milne 

 Edwards's examination of the corals. 



Professor Phillips, in his introduction to geology, has placed the 



