INDEX. 



Nigbt, the caufe of plants evaporating bad air and con- 

 taminating common air, p. 47. exp. 36 — 55. — Danger 

 of keeping plants in a room at night, p. 67. 



Nigbt-Jhade gives dephlogifticated air by day, exp. 63.— 

 Spoils common air by night, exp. 43. 



Nitre, its component parts, p. 1 18.—- What quantity of 

 dephlogiflicated air it yields, p. 118. 



Nitrous acid yields different kinds of air, p. 117. — Its 

 Wonderful effect upon metals, p. 121. 



Nitrous air. What ? p. liii. — A tell of the goodnefs 

 of refpirabie airs, p. 97 — 10S. — But fails in fome in- 

 stances, p. 99 and feq. exp. no — 115. — This already 

 difcovered by Dr. Prieftley, p. li. — how to produce it, 

 p. 170.— Its inconftant quality is a great fource of 

 errors in examining air, p. 169. — This difficulty over- 

 come by Abbe Fontana's method, p. 173. — The the- 

 ory of this, p. 174. — The befl manner of getting it of 

 a conftant quality, p. 170 — 279. — Why, in the me- 

 thod ufed by Dr. Prieftley, the remaining bulk of the 

 two airs is greater than in the abridged method fami- 

 liar to the author, p. 28_§\ 



Nympbaa Alba, its air-bubbles, p. 16. 



O. 



Oaky its peculiar nature in yielding air bubbles, p. l%. 

 — Its air by night, exp. 37.— Its air in the made, exp. 

 47. — Its faculty of contaminating common air by 

 night, and correcting it again by day, exp. 50. — Does 

 not infecl: air fo much as fome other trees, exp. 119. 

 — But fometimes much more (perhaps in very warm, 

 weather), p. 205. 



Old 



