90 



G-rams. 



(1) Weight of Tungsten hexachloride taken 19-5700 



„ Chlorine found 10-4901 



Percentage of Chlorine 53 -605 



(2) Weight of Chloride taken 10-4326 



„ Metal obtained 4-8374 



Percentage of Metal 46*368 



Hence the atomic weight of the metal is 184-25 ; or, taking 

 the mean of the two methods, we have 184-04 as the atomic 

 weight of tungsten. 



The author wishes to express his thanks to Mr. H. Rocholl 

 who has ably aided him in the above research. 



MICROSCOPICAL AND NATURAL HISTORY SECTION. 

 January 15 th, 1872. 



Joseph Baxendell, F.RA.S., President of the Section, in 



the Chair. 



A paper was read on Nemosoma elongata by Joseph 



SiDEBOTHAM, F.RA.S. 



The Author having discovered a considerable number of 

 specimens of this very rare species under bark of elm, at 

 Beeston, Notts., in November last, and having the oppor- 

 tunity, carefully observed its habits, of which he gave a 

 detailed account, illustrated by specimens and by portions 

 of bark and diagrams ; showing also specimens and drawings 

 of Hylesinus viitatiis, on which it is parasitic. 



Mr. Thomas Cowaed exhibited some tropical species of 

 Composit?e having some curious superficial resemblances to 

 species of widely separated orders. 



