44-2 



Seal, on the difference of the teeth 

 and shape of the skull in different 

 species of, ii. 168; on the stmcture 

 of the funis and placenta of, ii. 213. 



Second surfaces of transparent plates, 

 their action upon light, ii. 395. 



Seeds, on the direction of the radicle 

 and germen during the vegetation 

 of, i. 218. 



Sempervivum tectorum, the purest ma- 

 lic acid prepared from, ii. 23. 



Sepia and the Vermes testacea, distin- 

 guishing characters between the ova 

 of, ii. 75. 



Seppings (R.) on a new principle of 

 constructing ships of war, i. 496. ii. 

 80, with remarks on, by Dr. Young, 

 i. 498 ; by M. Dupin, ii. 62 ; on a 

 new principle of constructing mer- 

 cantile ships, ii. 125. 



Serpentiform fishes, on a newly disco- 

 vered genus of, ii. 302. 



Serpents, on the poisonous fangs of, 

 ii. 101. 



Sewell ( W.) on a canal in the medulla 

 spinalis of some quadrupeds, i. 325. 



Sex not given to the fcggs of birds, or 

 to the spawn of fishes or insects, at 

 any very early period of their growth, 

 ii. 347. 



Shark, ovo-viviparous, on the mode of 

 breeding of the, i. 374. 



Sheep, new variety in the breeds of, 

 i. 451. 



Shell-fish, burrowing and boring, on, 

 ii. 278. 



Shells: fossil, ii. 198, 220; worm- 

 shells, description of a rare species 

 of, i. 233, 234. 



Ship-building, on a new principle in, 

 i. 496, 498. ii. 62, 80, 125. 



Ships : mercantile, on a new principle 

 of constructing, ii. 125; on the ap- 

 plication of electrical combinations 

 to the preservation of the copper 

 sheathing of, ii. 207, 213, 242, 284. 



Ships of war : on a new principle of 

 constructing, i. 496. ii. 80 ; re- 

 marks by Dr. Young, i. 498 ; by M. 

 Dupin, ii. 62. 



Siamese twins, united, account of the, 

 ii. 397. 



Sight : a case of the recovery of, after 

 having been deprived of it by cata- 

 ract, i. 58 ; near and distant, obser- 

 vations relative to, i. 444, 454. 



Silver, discovery of in Herland copper- 

 mine, i. 42. 



Simons (Dr.) on the velocity of sound, 

 ii. 401. 



Sirius, its light compared with that of 

 the sun, ii. 355. 



Skiddaw, the height of, ii. 98. 



Sliding-rule, extension of the principle 

 of the, ii. 2. 



Smith (T.) on the poisonous fangs of 

 serpents, ii. 101. 



Smithson (J.), analysis of some cala- 

 mines, i. 102 ; on a discovery of na- 

 tive minium, i. 232 ; on the com- 

 pound sulphuret from Huel Boys, 

 i. 284 ; on the composition of zeo- 

 lite, i. 396 ; on a substance from 

 the elm tree, called ulmin, i. 447 ; 

 on a saline substance from Mount 

 Vesuvius, i. 474; facts relative to the 

 colouring-matters of vegetables, ii.8(5. 



Snakes: poisonous, on the orifices 

 found in, i. 138 ; hooded, on the 

 voluntary expansion of the skin of 

 the neck of, i. 157; on the progres- 

 sive, motion of, i. 424. 



Snow, red, on the fungi which consti- 

 tute the colouring-matter of, ii. 128. 



Snowdon, on the measurement of, ii. 

 132. 



Sobieski's Shield, on the changes of the 

 variable star in, i. 180. 



Solar and terrestrial light, some experi- 

 ments on, ii. 120. 



rays that occasion 



heat, experiments on, i. 23, 94. 

 eclipse: 7th Sept. 1820, calcu- 



lations of some observations of, ii. 

 150; predicted by Thales, on the, 

 i. 400. 



light, experiments on, i. 61. 



observations, the use that may be 

 drawn from, i. 49. 



rays, on magnetic influence in, 

 ii. 27, 263, 351. 



tables, Delambre's, corrections 



thereof required by the Greenwich 

 observations, ii. 328 ; required by 

 Mr. South's observations, ii. 305. 



Solids : on the attraction of such as 

 are terminated by planes, i. 433 ; 

 on the friction and abrasion of the 

 surfaces of, ii. 364. 



Somerville (Dr. W.) on the magneti- 

 zing power of the more refrangible 

 solar rays, ii. 263. 



