49o INDEX. 



Monro^ Dr. Donald, his accpunt of feveral mineral waters 

 in Scotland, p. 1 5. 



N. 



Nairne, Mr. contriver of a new dipping-needle, p. 476. 

 His experiments with it, p. 477. 



Natural Hiftory, its progrefs during feveral centuries and 

 among different people, p. 295. 



Newland, Capr. Charles, obfervations in a voyage to 

 the Red Sea, p. 77, 78, &c. His method of di- 

 fHlling frefji from fea water, p. go. His obfervations 

 on the miJky appearance of Tome fpots of water, p. 



93- 

 Nicomachus, Extracts from his arithmetic about Eratof- 



thenes's fieve corrected and explained, p. 339. 



Nightingales, whether they can migrate at any diftance ? 

 p. 300. Not attended to at certain times, p. 32. 



Nitrous air, formed from a folution of metals in fpirits 

 of nitre or aqua regia, p. 2io„ Its redpction of 

 common air, p. 211. The beft teft of the fitnefs 

 of air for refpiration, p. 214. Irs phenomena with 

 different kinds of noxious air, p. 215, 216. Re- 

 duced to one fourth by a mixture of iron filings and 

 brimftone, p. 217. Noxious to plants and animals, 

 ibid. Readily abforbcd and obftinately retained in wa- 

 ter, p. 218, 210. A great preierver from putrefaction, 

 p. 223. Proportion in which it may be got from fe- 

 veral metals, p. 322. 



Nu-mbers % See Prifflfo 



O, 



Oak t a new fpecies obferved and reared by Mr. Lucomfre, 

 128. Irs fpeecy growth deicribed by Mr. Holwtll, p. 

 1^9, &c. 

 ObeieSi Six in a dram, p. 470. 



€n a tkt 

 6 



