CONTENTS. 
I. Description of a Percussion Shell , to he fired horizontally from 
a common gun . By Lieutenant Colonel Miller, late of the 
Rifle Brigade , and now unattached. Communicated by R. I. 
Murchison, Esq. F. R. S. - - page 1 
II. On the relative powers of various metallic substances as con- 
ductors of electricity , By Mr. William Snow Harris, of 
Plymouth, Surgeon, Communicated by J. Knowles, Esq . 
F. R. S. November 1826. - - 18 
III. On the expediency of assigning specific names to all such 
functions of simple elements as represent definite physical pro- 
perties ; with the suggestion of a new term in mechanics; 
illustrated by an investigation of the machine moved by recoil , 
and also by some observations on the Steam Engine. By Davies 
Gilbert, Esq. M. P. V. P. R. S. &c. 25 
IV. The Croonian Lecture for 1826. By Sir Everard Home, 
Bart. V. P.R. S. - - - 39 
V. On a newly discovered genus of Serpentiform Fishes. By 
I. Harwood, M. D. F, L, S. Professor of IN' atural History 
in the Royal Institution of Great Britain. Communicated by 
Daniel Moore, Esq. F. R. S. - - 49 
VI. An examination into the structure of the cells of the human 
lungs ; with a view to ascertain the office they perform in res- 
piration. By Sir Everard Home, Bart. V. P. R. S. Illus- 
trated by microscopical drawings from the pencil of F. Bauer, 
Esq. F.R. S. - - - - 58 
