148 Proceedings of Philosophical Societies. [Feb. 



13. Mercury absorbs a of its weight of the peculiar substance, 

 and hence seems to combine with two atoms. 



14. Sir H. Davy calculates the weight of the peculiar acid (on 

 the supposition that it is a compound of equal bulks of the peculiar 

 substance and hydrogen) condensed into half their bulk at 95*27 

 grains for 100 cubic inches. 



15. The peculiar substance is not decomposed by Voltaic elec- 

 tricity. It is negative with respect to most substances, but with 

 respect to chlorine it is positive. 



16. We must consider it as an undecomposed substance ana- 

 logous to chlorine and fluorine. Sir H. Davy proposes to call it 

 iodine. The acid which it forms with hydrogen he calls hydrionic, 

 the acid with chlorine chlorionic acid, that with tin sUamiomc. Its 

 compounds with metals may be called lodes. 



He concludes the paper by making another proposal as to 

 nomenclature. To distinguish the combinations of fluorine by the 

 letter I, of chlorine by the letter n, and of iodine by the letter m, 

 the vowels representing the number of atoms. Thus cdlca is a 

 combination of an atom of calcium and an atom of oxygen ; 

 calcala, a combination of an atom of calcium with an atom of 

 fluorine ; ccdcana, a combination of an atom of calcium with an 

 atom of chlorine ; calcama, a combination of an atom of calcium 

 with an atom of iodine. 



LINN^AN SOCIETy. 



On Tuesday, the 18th of January, the remainder of Mr. 

 Marschal Von Bibei-stein's paper on the genus serratula was read. 

 He described 18 species. He described, likewise, about 14 species 

 of a new genus, distinguished by the name of heterotrickm, con- 

 sisting of species removed from the genus serratula, on account of 

 the different structure of the pappus. 



At the same meeting a notice by Mr. Sowerby was read, respect- 

 ing the tremella metsorica, a gelatinous matter ranked among 

 vegetable substances. He requested information whether it was an 

 animal or vegetable substance. He mentioned, at the same time, 

 several other gelatinous substances, concerning the animal or 

 vegetable nature of which doubts were entertained. 



GEOLOGICAX. SOCIETY. 



At a meeting of the Society on the l7th of December, the conti- 

 nuation of Mr. Webster's paper on the upper strata of the S. E. 

 part of England was read. 



This part of Mr. Webster's paper begins by a description of the 

 marine deposit which covers the lower fresh water formation in the 

 Isle of Wight. The place where it may be studied to most advail- 

 tage is Headen, near Alum Bay. It here appears about half way 

 up the cliff", is about 3o feet thick, and dips a few degrees to the 

 North. The substance composing the principal part of the bed is 

 a pale greenish marl, filled with small shells chiefly cerethia, and 

 cytherea and oysters, in a very perfect state of preservation. Th» 



