INDEX. 369 



o. 



Osmium. Method of obtaining its oxide in a pure solid and crystallized state, 8. 



P. 



Palladium. Method of obtaining it malleable, 7. 



Pendulum {Convertible). On the reduction to a vacuum of Captain Kater's pendulum, 



331 e/ seq. 



{Invariable). Its comparative vibration in air and in a vacuum, 236. 



Its retardation by atmospheric air and by hydrogen gas not strictly 



proportionate to their respective densities, 231. 



{Seconds). Its comparative rate at London and Greenwich, 87. 



Pepys,( William Hasledyne, Esq.). On the respiration of birds, 279 et seq. 



Philip (Alexander Philip Wilson, M.D.). On the functions of digestion, 137 et seq. 



On the functions of the nervous system, and 



on their relation to other vital functions, 261 et seq. 

 Platina, On a method of rendering it malleable, 1 et seq. 

 Its tenacity and specific gravity, 6 & 7. 



Q. 



Quantities {algebraic). Capable of geometrical representation, S^O. 



• {negative). On the geometrical representation of their square roots, 241 et seq. 



R. 



Rennie (George, Esq.). Experiments on the friction and abrasion of the surfaces of 



solids, 143 et seq. 

 Respiration. Of pigeons in atmospheric air, pure oxygen, and a mixture of hydrogen and 



oxygen, 279 et seq. 

 Ritchie (William, M.A.). Experimental examination of the electric and chemical 



theories of galvanism, 361 et seq. 



S. 



Sabine (Captain Edward). On the dip of the magnetic needle in London in August 1828, 

 ^1 et seq. 



—— Comparison of the seconds pendulum in London and Green- 

 wich, 83 et seq. 



• Reduction to a vacuum of an invariable pendulum, 207 et seq. 



Notice on the reduction to a vacuum of Captain Kater's pen- 



dulum, 3S1 et seq. 



Sapphire Letts. Its superiority over every single lens hitherto employed for microscopes, 9. 

 Sirius. Its light compared with that of the Sun, 23. 



Sun. Its light compared with Sirius, 23 ; with a candle, 27 ; with the Moon, 27. 

 MDCCCXXIX. 3 B 



