INDEX. 399 



Plumbago, notice of artificial, in coal-gas retorts, 159 



Pond (John, Esq.), predicted and observed places of the prin- 

 cipal stars, 135 



Port-Royal Mountains, Jamaica, barometrical measurement of 

 the height of, 70 



Potash, observations on the crystalline forms of the salts of, 

 282—288. Effects of the boracic acid on the acid fluate of 

 potash, 303. Experiments on the hydroxanthate of potash, 

 305 — 307. Combinations of the chromic acid with potash, 

 310, 311 



Potassium (Sulphuret of), experiment on, 149. On' the pre- 

 paration of potassium, 380, 381 



Potato, wild, on the native country and culture of, 259 — 266 



Preservation of echini, asterise, crabs, &c., 172, 173. Of ana- 

 tomical preparations, 391 



Pressure and heat, action of, on certain fluids, 145 — 147. Elec- 

 tricity produced by it, 368. Light evolved by it, ibid. 



Printing, improvement in, 138 



Prize Question: — On the magnetism of the solar rays, 163 



Q 



Quartz, analysis of crystallized stalactitic, 169 



R 



Rain, fall of, in the tropics, 167 



Red Ware, new glaze for, 142 



Reflecting Telescopes, mode of protecting the specula of, 52 



i?e/rac<iow, empirical elements of a table of, 128 — 131. Re- 

 marks on Mr. Plana's researches relating to refraction, 362 

 —366 



Resistance of air, determined from Captain Kater's experiments 

 on the pendulum, 351 — 356 



Hespiration, action t)f nitrogen in, 386 



Robiquet (M.) experiments of, on the volatile oil of bitter 

 almonds, 155 



Rock Specimeiis, from North America, account of, 11 — 22 



Rotation (Electro- Magnetic), historical statement respecting, 

 288—292 



Royal Society, proceedings of 164 ; 292, 293 



Rumker (Charles) re-discovery by, of Encke's triennial comet, 

 132—134 



S 



Sabine (Captain), details by, of a barometrical measurement of 

 the sugar-loaf mountain at Sierra Leone, 67 — 69. Of the 

 mountain-house at Ascension, 69. Of the block-house at 

 Fort-George, Trinidad, 70. Of Port Royal mountains, Ja- 

 VoL. XV. 2 D 



