INDEX. 



Principle, fermenting, opinions refpe£llng 

 24 — Experiments to difcover it, 35 — Is 

 of an animal nature, 36— -Chemical 

 properties of, 39 — Theory of its ac- 

 tion, 42 



Prize adjudgad by the National Inftitute, 

 159 



■ I for the artificlal produftion of pal- 

 ladium, 75, 159 



J*rognoftics of the weather, 148 



Prouft on a dangerous fulminating pow- 

 der, 77 



Pruffiate of potafh, aftion of alcohol on, 

 285 



Pump with a double plunger, defcription 

 of, 5z 



Queftions, optical, 71, Z36 



- prize, 159, i6o, 318 



^ 



R. 



Rain, figns of, 149, 154 



Rainbow, figns of the weather from, 15a 



Rattle-fnake, memoir on its fafcinating 

 qualities, 270— Is held in veneration by 

 fome North American ladians, 275 



Repeater, conftrudlion of a fimple, 167 



Ritter, Mr. abftradl of his memoir on gal- 

 vanifm, 288 



Rivatz, 315 



Roover's de, method of reftoring rancid 

 eflential oils, 68 



Rouelle, 33 



Roy, Gen. 108 



Rubbers for electrical machines, improve- 

 ment in, 125 



Sade, Chev. de, on the extinft volcanoes 

 in the environs of Coblentz, 136 



Safety valve for digefters, 164 



Salt, chemical examination of a new one 

 obtained from the mulberry, 129 



Savery's fte&m engine, 31! 

 Schnaubcrt's new method of prepariilj| 



pure Gallic acid, 74 

 Scoteography, or art of writing In the 



dark, 53 

 Screw, double, account of, 51— Its uti- 

 lity in meafuring, 52 

 Seafons, peftilential, figns of, 156 

 Seguin, 43 



Serpents, American, memoir on their faf- 

 cinating faculty, 270 

 Shadows, coloured, memoir on, 23— 

 Variety of the tints produced by two 

 lights, ib.— CompleAentary colours of^ 

 24 — Are probably occafioned by the na- 

 ture of the combuftible, 28 — Si^imary 

 of the experiments on, 29 

 Sharplefs, Mr. defcription of his appara- 

 tus for raifing water, 298 

 Shaving, obfervations on, 240 

 Sheep, queftion refpefting the beft mode 



of treating the vertigo in, 318 

 Shot, double-headed, probable effefts of 



the ufe of, 147 

 Signs of the weather, 148 

 Silver, preparation of a fulminating mu« 

 riate of, 285 — Its application on porce- 

 lain unfuccefsful, 286 

 Sky, queries refpe£ling Its figure, 71, 239 

 Sloane, Sir H. 283 

 Smith, Dr. 143, 292 



Dr. J. E. 279 



Snow, flafhes of light during, 57 



Soap of wool, produced by the aftlon of 



the galvanic pile, 320 

 Sound, chemical aftion of, 122 

 SpeiSlacles, improvement in the form of 

 ■ the glafles, 143 — Notice of the various 

 attempts at improving, 194 — Have not 

 been fo much attended to as other op- 

 tical inftruments, 291 

 Speculum, concave, queries refpefting the 



place of the image in, 71, 236 

 Spirits, experiments on the evaporation 



of, 13 

 Stahl, 33 



Start, 



