of, assuming the interior of the earth
to be fluid and heterogeneous, 115,
129, 367.
Observatory at Ardwick, description of, 371.
Oceine, chemical examination of, 233, 337.
Ohm (Dr.), a Copley medal awarded to, for his researches into the laws of electric currents, 336.
Olbers (Dr.), notice of the late, 267,
Ohbanum, resin of, 163.
Operculum, traces of progressive stages of its growth remain on it, 80 ; its spiral a logarithmic spiral, 80.
Opoponax, resin of, 219, 241.
Ornithorhynchus hystrix, on the form of the blood-particles of the, 232.
Otaheite, new determination of the magnetic elements at, 288.
Ovisac, on the origin and structure of the true, a vesicle common to all vertebrated animals, 73 ; in mam- malia, &c., 74; cavity in which often found, 75 ; peculiar granules of the, 75 ; the fluid contained in the, 75 ; parasitic ovisacs, 75.
Ovum, the germinal vesicle and its contents are those parts which are first formed, 74 ; disappearance of ova and formation of others, 75 ; the ovum conveyed to the periphery of the Graafian vesicle, 75 ; the order of formation of the more permanent parts of the ovum and the Graafian vesicle in mammalia, 76 ; the ma- ture and immature, 137; effects produced on, in the ovary by mace- ration, 137; in the ovary post coi- tuMy 137; locality in which fecun- dated, 137; discharge of from the ovary, 137; the ovum after it has left the ovary, 138; its minute size no criterion of the degree of its de- velopment, 139; abortive ova, 139; may pass through at least one-and- twenty stages of development before it has attained the diameter of half a line, 139; some of the earliest appearances of the, 139; changes in the ovum consequent on fecun- dation, 222 ; no fixed relation be- tween the degree of development of ova, and their size, locality or age, 224; the elements of the, compared with corpuscles of the blood, 324.
Ovum, mammiferous, discovery of the germinal spot in the, 279 ; sperma- tozoa observed in, 432.
Oxmantown (Lord), experiments on the reflecting telescope, 238.
Oxus, the river, discovery of the source of, 83.
Oxygen, the equivalent numbers of, 123.
Palgrave (SirF.), account of the shoot- ing stars of 1095 and 1243, 210.
Palladium, on the chemical history of the compounds of, 379.
, on the reduction of, 447.
Panizzi's (Mr.) pamphlet, statement of the Council relative to, 18.
Paper, sensitive, on a new kind of, for photographic purposes, 134.
Parallel roads of Glen Roy, and of other parts of Lochaber in Scotland, on the, ] 27.
Parat (D.), nouveaux faits a ajouter a la theorie de la chaleur et a celle de I'evaporation, 473.
Parish (Sir W.), barometrical observa- tions taken at Naples, 303.
Pena silver, experiments on, 119.
Pendulum, on the vibration of the, 78.
Penny (F.) on the application of the conversion of chlorates and nitrates into chlorides, and of chlorides into nitrates, to the determination of equivalent numbers, 119.
Pepys (W. H.) on the respiration of the leaves of plants, 466.
Percussion shell, to explode at the bottom of the sea, 248.
Phillips (Capt. C), notice of the late, 262.
Phillips (R.) on the chemical equiva- lents of certain bodies, 123.
Phosphates, on the, 162.
Photogenic drawing, on the art of, 120.
Photography, preparation of photoge- nic paper, 124, 134.
, account of the processes em- ployed in photogenic drawing, 124.
, on fixing the image, 125,
, on the art of, 131.
, influence of iodine in rendering
argentine compounds, spread on paper, sensitive to light, 239.
, improvements in, 312.
, on fixing, taking copies and
transfers, and the preparation of the paper, 206.
