376 Proceedings of the British Association. 



Section B. — Chemistry and Mineralogy. 



CJmirman — Dr Hope. 



Deputy -CJiairmen — Dr D Alton. Dr Thomas Thomson. 



Secretaries — Professor Johnston. Dr Christison. 



Committee, — Dr Daubeny. Dr Turner. Dr Lloyd. Rev. W. 



V. Harcourt. Thos. J. Pearsall, Esq. WiUiam Hatfield, Esq. 



Dr Traill. Dr Gregory. Dr Thomas Clark. Thomas Graham, 



Esq. Arthur Connell, Esq. Luke Howard, Esq. Dr Apjohn. 



Charles Tennant, Esq. Charles Macintosh, Esq. William West, 



Esq. Richard Phillips, Esq. George Lowe, Esq. 



The Chemical Section having met at 11 a. m., the proceedings of 

 the Committee were read over, and Dr Hope took the chair, in 

 conformity with the request of the Committee. 



The recommendations of the Chemical Committees of the former 

 meetings of the Association were then read over and severally con- 

 sidered. 



In regard to the specific gravities of the gases, Dr Dalton stated 

 that he was not prepared with any results on this subject in a state 

 to be laid before the Section. 



^ Dr Turner made some remarks on his experiments on atomic 

 weights, published in the Transactions of the Royal Society of Lon- 

 don, and on the conclusion he had come to that the atomic weights 

 of bodies cannot be represented by whole numbers. On this sub- 

 ject a discussion of some length took place, in which many mem- 

 bers took part. 



Mr Johnston and Mr Harcourt gave an account of the state of 

 the experiments they have respectively undertaken, on the compa- 

 rative analysis of iron in the diiferent stages of its manufacture, and 

 on the effects of long-continued heat. 



In regard to the purity and specific gravity of mercury, Dr 

 Thomson stated that he considered the mercury as imported into this 

 country to be pure, and that he believed the determination of the 

 specific gravity of mercury, as given by Mr Cavendish, to be cor- 

 rect, as it agrees with that of Mr Crichton of Glasgow, lately de- 

 duced from a very great number of careful experiments continued 

 throughout a whole winter. 



Dr Daubeny, on the subject of the seventh recommendation, viz. 

 an inquiry into the nature and quantity of the gases given off from 

 thermal waters, and the effects of season and other circumstances 



