140 CORRESPOiVDING SOCIETIES. 



together with silicate of ahimina and combined water, and minute quantities 

 of other materials. The best account of these marine nodules with drawings 

 occurs in M. J. Thoulet's Oceunognipliie, 1890. 



Both in appearance and composition it is clear that the nodules described 

 by Miss Thresh have the closest resemblance to these marine nodules. This 

 suggests a common origin and that the former were not formed in situ, but 

 that during the ice age they were picked up by floating icebergs from the sea 

 bottom along with other material and transported to and deposited in their 

 present position. This being so, their occurrence in the Boulder-clay and not 

 in the London-clay soils is owing, not to the necessity of chalk for their produc- 

 tion as suggested by Miss Thresh, but to the fact that the Boulder-clay is a 

 glacial deposit and the London-clay is not. 



The explanation given by Miss Thresh of the formation of the nodules is 

 that which has been advanced by Dieulafait (Comptes Reudiis, 1883, p. 718) 

 for those of marine origin, who states that solution of manganese carbonate 

 exists in sea water and that this is attacked by the dissolved oxj^gen with 

 liberation of carbonic acid gas and deposition of manganese peroxide. 



The importance of the matter lies in the fact that if the nodules are of 

 marine origin, valuable light is thus thrown upon the source of the Boulder- 

 clay in which they occur. 



T. S. DYMOND. 



[Count)' Technical Laboratories, Chelmsford, December, 1901.] 



THE CORRESPONDING SOCIETIES COM- 

 MITTEE OF THE BRITISH ASSOCIATION, 

 GLASGOW, 1901. 



REPORT OF THE CLUB'S DELEGATE, 



F. W. RUDLER, F.G.S., Chairman of the Conference. 



The Lecture Theatre of Medical Jurisprudence, in the 

 University Buildings, was placed at the disposal of the 

 Delegates throughout the Association week. Two meetings of 

 the Delegates were held here -one on Thursday, Sept. 12th, and 

 the other on Tuesday, Sept. 17th. The Chairman at these Con- 

 ferences was the delegate of the Essex Field Club, Mr. F. W. 

 Rudler ; the Vice-Chairman was Mr. W. VVhitaker, F.R.S., and 

 the Secretaries were Dr. J. G. Garson and Mr. A. Somerville. 

 The meetings were well supported, no fewer than 42 societies 

 having sent delegates. 



The Chairman opened the proceedings with an informal 

 address, in which he suggested the local societies should regard it 

 as part of their duty to seek, register, and record in a systematic 



