INDEX. 



489 



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. 



c2 



