8G8 REPORT — 1902. 



It was agreed that the several subjects mentioned on pages 852 and 

 853, which were selected last year for investigation by the Corresponding 

 Societies, be retained on the list and again recommended to them for 

 investigation during the ensuing year, except No. 6, which is to be omitted, 

 and No. 18, which has been amalgamated with No. 9. 



No representative of Section A (Mathematics and Physics) was present. 



Professor E. A. Letts, D.Sc, Ph.D., as a delegate from Section B 

 (Chemistry), called attention to Dr. Gladstone's communication on the 

 phosphorescence and fluorescence of diamonds, and suggested that oppor- 

 tunity should be taken of examining as many specimens as possible. 



In a paper by Mr. J. S. Totton and Dr. Letts the functions of aquatic 

 vegetation in absorbing certain of the nitrogenous constituents of sewage 

 were dealt with, and reference was made to a previous communication by 

 Mr. J. Hawthorne and Dr. Letts on the Seaweed Ulva latissima and its 

 relation to .sewage pollution of sea-water. It was shown (1) that its 

 tissues contain a very high proportion of nitrogen ; (2) that it absorbs 

 ammonia and nitrates with great rapidity from sea-water either naturally 

 or artificially contaminated with those substances ; (3) that the Ulva only 

 occurs in quantity in those localities where the sea-water is polluted with 

 sewage ; and (4) that in both Dublin Harbour and Belfast Lough, which 

 are localities of the kind, a serious nuisance is caused annually by the 

 putrefaction of the seaweed when washed ashore. Professor Letts said 

 that he would be very glad if those members of the Corresponding Socie- 

 ties who were botanists would keep this seaweed under observation, and 

 would report its occurrence in quantity in any particular district, together 

 with the local conditions as to pollution, &c. 



Professor Grenville A. J. Cole, M.R.I.A., P.G.S., represented Section 

 C (Geology), and summarised the more important work put before the 

 Section, pointing out how local observation might assist in clearing up 

 such problems as those of the Pomeroy Rocks, the distribution of northern 

 erratics, etc. 



Dr. H. Woodward, F.R.S., called the attention of the Delegates to 

 the importance of registering all type-specimens of fossils in the British 

 Isles. Many types were buried in local museums, and the various 

 Corresponding Societies would do excellent service to science by securing 

 their registration. 



Mr. W. E. Hoyle, M.A., representing Section D (Zoology), referred to 

 the work in this Section which might be assisted by local observers. 

 Such subjects as the investigation of the insect-fauna of Irish caves, and 

 observations on mimicry in British insects, were cited as suitable for 

 certain local societies. 



Dr. H. R. Mill, F.R.S.E., attending as a representative of Section E 

 (Geography), said that he had more than once had occasion to be 

 grateful to Local Societies for important assistance in collecting material 

 for the comprehensive discussion of natural phenomena. There were 

 sometimes difficulties in the way of such societies carrying out researches 

 which demanded the knowledge and application only to be expected from 

 specialists who devoted their whole time to the subject ; but the collection 

 of data was an essential preliminary to all scientific work, and for this the 

 societies were admirably suited. There was one way in particular in 

 which he believed the members of Local Societies, esjaecially those in 

 Ireland, could find interesting occupation sure of leading to useful 

 scientific results. He was devoting himself to the collection and discua- 



