INDEX. 



Playfair, Mr. en the origin of mountains. 



Plum-tree bark yields a fine Carmelite 

 dye, 230 



Poplar (Italian) bark ufed as a yellow 

 dye, 230 



Pneu.^j, Dr. on air contained in red- 

 lead, 91, 233 



Prize Queftions by the Royal Academy 

 of Sciences at Berlin, 182. — By the 

 Univerfity of Vilna, i8z 



Profpeflus of a Chemical Society in 

 London, 268 



Proud, M. on tin and its compounds, 

 38. — His Analyfis of Zinc, 136.^ — 

 On the fugar of grapes, 178. — His 

 fads towards a hiftory of gold, 238, 



331 

 Purple of Cafliu;, analyfis of, 331 



Quericif refpefting the incruftation left 

 by water upon iron boilers, 1S9. — 

 On the taking off counter-proofs from 

 engravings, ib.— On the imperfeftions 

 of fpecuJums, ibj — Rcfpeding the 

 fuppofed achromatic eye-glafs, ib.— 

 Anfwered, 190 



Quefnaj, Dr. 184 



Quinquina compound with other vege- 

 table produftions in a medicinal point 

 of view, 57 



Razors recover their edge after being laid 

 afide, 89, 92.— Method of keeping in 

 temper, 3-^5 



R. B. Letter of inquiry from, refpefting 

 the caufe why men cmnol fwim with- 

 out previous inftruftion, as well as 

 brutes, 324 



Refleilion, fingular appeaiance occafion- 

 cd by, 340 



Rey's dodVrine that metals aequir? vreSght 



in oxidation from the air, 231 



Richter on light, 165 



Richardfon, Mrs. her method of clearing 

 feathers of their animal oil, a66 



Robifon, Profeffor, 236 



Roy's mcnfuration of heights by the nfe 

 of the barometer, 1 



Rozier, Abbe, 214 



Rumford, Count, on the difperfion of 

 the light of lamps by means of fhades 

 of filk, &q. 22.— His improved lamp 

 defcribed, 33. — On the mode of ths 

 propagation of heat in liquids, '^^^ 



RuHian manufcripts, 351 



Rutherford, Dr. his opinion of fulphuric 

 acid prior to the publication of La- 

 voifier's, 236 



Schecle, 161, 163 



Scientific News for May, 179 — For June, 

 268— For Juiv, 350 — For Auguft, 

 4ZI 

 Sedillot, M. 63 

 Seeds, vegetation of, 409 

 Shades of roughened glafs do not intercept 

 the rays of ligbt, but thofe of gauze* 

 &c. do, 25, ctfe^. 

 Shaving, fads relating to the ar t q 



344 

 Shuckburg, Sir G. his endeavours to 

 facilitate the menfuration of heights 

 by means of the barometer, i 

 Ships ftruck by lightning, enumeration of 



feveral cafes of, 318 

 Ship's velocity, meafure of, 343 

 Shoe-making, machine for performing in 



a ftanding pofture, 155 

 Silver coins analyzed, 396 

 Smith, Dr. Adam, 184 

 Soils, bsft varieties of, 154 

 Solids and fJuids, cohefive attradion of, 



88, 158 

 Speculums, imperfeftions of, 189 



Spring 



