90 
Grams. 
(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 loth, 1872. 
Joseph Baxendell, F.R.A.S., President of the Section, in 
the Chair. 
A paper was read on Ne mosomci elon gat a by Joseph 
SlDEBOTHAM, F.R.A.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 viitatus, on which it is parasitic. 
Mr. Thomas Coward exhibited some tropical species of 
Compositre having some curious superficial resemblances to 
species of widely separated orders. 
