NIM 



NOB 



NEUTRAL SALTS. Formerly, salts 

 in which the base was perfectly saturated 

 with the alkali, thus possessing neither 

 an acid nor an alkaline character. The 

 terra now denotes those compounds, 

 which are composed of one equivalent 

 of each of their constituents, without 

 reference to their taste, or to their action 

 on coloured tests. 



NEUTRALIZATION. A term gene- 

 rally applied to the decomposition of the 

 alkaline carbonates, by the addition of 

 some acid more powerful than the car- 

 bonic acid, which is consequently ex- 

 pelled from the alkaline bases with eflfer- 

 vescence. 



NEW RED SANDSTONE. A forma- 

 tion consisting chiefly of sandy and 

 argillaceous strata, the predominant co- 

 lour of which is brick-red, though it 

 contains portions which are of a greenish- 

 grey. The striped and spotted appear- 

 ance of this series has caused it to be 

 sometimes termed variegated sandstone. 

 This formation has been divided into the 

 Upper New Red, in which Muschelkalk 

 is included, and the Lower New Red, 

 of which the Magnesian Limestone is a 

 member. 



NICKEL. A metal of a colour inter- 

 mediate between those of silver and of 

 , tin, and commonly obtained from its 

 sulphuret, the kupfernickel of the Ger- 

 mans, which is generally mixed also 

 with arsenic, iron, and cobalt. The sul- 

 phuret was formerly called capillary iron 

 pyrites, and afterwards considered as 

 native nickel, till its real composition 

 was determined by Arfvedson. 



NIDAME'NTAL (nidM^, anest). Re- 

 lating to the protection of the egg and 

 young, especially applied to the organs 

 which secrete the materials of which 

 many animals construct their nests. 



NlDITE'LiE {nidus, a nest, tela, a 

 web). A family of Spiders, which weave 

 a nest, from which issue threads to en- 

 trap their prey. 



NIGRINE. An ore of titanium, con- 

 sisting of this metal and iron. 



NFHIL ALBUM. A former name of 

 the flowers or white oxide of zinc, Lana 

 philosophica was an equally curious de- 

 signation of the same substance. 



NIM:^US, or CUMULO-CIRRO- 

 STRATUS. The rain-cloud; a compo- 

 site modification of clouds, resulting 

 from increase of density and deepening of 

 shade in the cumulo-stratus, indicating 

 a change of structure, which is always 

 followed by the fall of rain. All the 

 233 



other forms of cloud may increase so as 

 to obscure the sky, and dissolve without 

 falling in rain; but the nimbus, once 

 formed, is always followed by rain or 

 snow. 



NINTH. A dissonant interval in 

 Music, retarding the eighth and resolv- 

 ible into either the sixth or the third. 

 The major ninth consists of six tones 

 and two semitones ; the minor ninth, of 

 five tones and three semitones. 



NI'TRATES. Compounds of nitric 

 acid with the salifiable bases. 



NITRE. Saltpetre, or nitrate of pot- 

 ash. When fused, and poured into 

 moulds, it is called sal prunella, or crys- 

 tal mineral; when mixed with charcoal, 

 and burnt, the residuum was formerly 

 called clyssus of nitre ; mixed with car- 

 bonate of potash and sulphur, in a warm 

 mortar, it forms the fulminating powder ; 

 mixed with sulphur and charcoal, it 

 forms gunpowder ; and when mixed with 

 sulphur and fine saw-dust, it constitutes 

 the powder of fusion. 



NITRIC ACID. A constituent of 

 nitre or saltpetre, existing only in com- 

 bination, and named, from its corrosive 

 properties, aquafortis. 



NI'TROGEN {virpov, nitre, ^evrnw, to 

 produce ; so called from its being a gene- 

 rator of nitre). Azote. An elementary 

 principle, constituting four-fifths of the 

 volume of atmospheric air. It was 

 formerly called mephitic air, and, by 

 Priestley, phlogisticated air. 



1. Nitrous Oxide. Formerly called by- 

 Priestley, who discovered it, dephlogisti- 

 cated nitrous air; but more properly, 

 protoxide of nitrogen. Its common name 

 is laughing gas. 



2. Nitric Oxide, or nitrous gas. For- 

 merly called nitrous air ; but, more pro- 

 perly, deutoxide of nitrogen. When 

 mixed with atmospheric air, nitrous acid 

 vapours are produced, of a red or orange 

 brown colour. 



3. Nitrous Acid. Formerly called 

 fuming nitrous acid ; an acid of un- 

 certain constitution, termed hyponitrous 

 by Turner. 



4. Peroxide of Nitrogen. A compound 

 forming the principal part of the nitrous 

 acid vapours above mentioned. This 

 is the nitrous acid of Turner. 



NITRUM FLAM MANS. Nitrate of 

 ammonia, so named from its property of 

 exploding, and undergoing total decom- 

 position at the temperature of 600°. 



NOBILl'S FIGURES. The name 

 given to an electro-chemical phenomenon, 



