INDEX. 
page 
M 
Marcet, Alexander, M. D. on the specific gravity and 
temperature of sea waters, in different parts of the 
ocean, and in particular seas ; with some account of 
their saline contents, - ]6l 
Mists , some observations on their formation in particular 
situations, - - - 123 
N 
Needle, magnetic, on the anomaly in the variation of it as 
observed on ship-board, > - 96 
— — — — observations on the dip and variation of 
it, and on the intensity of the magnetic force; made 
during the late voyage in search of a north-west pas- 
sage, - * -132 
Needles, compass, on the irregularities observed in the 
direction of those of H. M. S. Isabella and Alexander 
in their late voyage of discovery, and caused by the 
attraction of the iron contained in the ships, - 112 
O 
Observations, multiplied, on the estimation of the advantage 
to be derived from them, - 70 
Ocythoe, on that genus, - - - 107 
Opossum , on the ova of that tribe, - - 234 
Ornithorhyncus , on the ova of that tribe, - 234 
Ovarium , human , its natural structure described, 59 
P 
Pendulum, rolling, Euler’s formula for it, - 94 
Pendulum vibrating seconds, an account of experiments for 
determining the variation in its length, at the principal 
stations of the Trigonometrical Survey of Great Bri- 
tain, - 357 
— — — description of the one used in 
the above experiments, - - 341 
— — — — — — the mode of determining its ex- 
pansion, and a statement of the results, - 343 
