INDEX. 



547 



Page. 



61 . — A single polarising axis may be the resultant 

 of any number of equal axes of an opposite cha- 

 racter, 63. — Resolution of the single axis into dif- 

 ferent numbers of axes, 65. — The same principle 

 applied to the 2d and 3d classes of primitive 

 forms, 67. — Intensity of the resultant axis in the 

 Rhomboid, for different inclinations, 71. — Ditto 

 in the Octohedron, 73. — General law represent- 

 ed by formulae, 74. 

 Crystals, Additional Observations on the Primitive Forms 

 of, by David Brewster, LL. D., 337. — The right 

 prism, with a square base, included in the 1st 

 class of primitive forms, 328. — 1st Class of pri- 

 mitive forms, 339. — Crystals with one axis divid- 

 ed into positive and negative, 340. — System of 

 Professor Mohs, 341. Comparative view of 

 Haiiy's primitive forms, with Mohs's fundamental 

 forms, and the optical system, 342. — Minerals 

 which ought to have a different primitive form 

 from that assigned them by Hatiy, 344. — Fun- 

 damental forms of minerals determined by Mohs, 

 345. — Primitive forms of minerals and crystals 

 not determined, 348. 



with one axis divided into positive and negative, 340 



Crystallization, principle of - - 262 



Cuticle, Nails, Hair, Feathers, and Plants, on the nutrition 

 of, by Henry Dewar, M. D., 272. — All the ele- 

 ments of a living body, to be found in dead mat- 

 ter, 274. — No evident law for securing the per- 

 manence of organized species of Being, ttJ5. — 

 Enquiry concerning the progress of nutriment, 

 276*. — Vessels may be of too minute calibre to 

 admit of circulation, 278. — No trace of vessels at 

 the extremity of feathers, 281. — Nourished by a 

 halitus, 283. 



M m 2 



