2 TKANSACTIOXS AND PROCEEDINGS OF THE [Sess. lxi. 



made with very simple apparatus, viz. a bell jar, a basin 

 and some lime-water, and a few mice. He put the lime- 

 water in the basin and inverted over it the bell jar. Under 

 the bell jar he slipped a mouse and watched its behaviour. 

 "When it began to show signs of distress he pulled it out 

 by means of a string tied to its tail and slipped in another 

 in its place. The second mouse showed signs of distress 

 much sooner than its predecessor, and another mouse was 

 substituted, who succumbed in a still shorter time. On 

 continuing the experiment it was found that the air under 

 the bell jar had grown smaller in bulk, and that it was of 

 a kind that a mouse could not endure with comfort for a 

 moment. This was the second great constituent of the 

 atmosphere, to which Lavoisier in after years gave the 

 name of Azote, to signify that it was a gas in which animals 

 could not live. For the same reason the Germans call it 

 stickstoff or choking stuff, while we in this country call it 

 nitrogen, which means the nitre maker, for it is found in nitre 

 as a very cliaracteristic constituent along with oxygen — 

 the nitrous spirit of Mayow. Later researches showed that 

 this gas, nitrogen, in which an animal could not breathe and 

 a candle could not Ijurn, occupied about four-fifths of the 

 entire atmosi)here, the remaining fifth being oxygen. 



The properties of nitrogen were studied by many chemists, 

 but it was found to be a very uninteresting subject. It 

 formed very few compounds, and its disinclination to unite 

 with other elements earned for it the name of the chemical 

 bacheh^r. It was found to be an idle, inert kind of a 

 loafer, good for nothing but to get in the road of the 

 molecules of oxygen and interfere with their oxidising 

 work, for Ijefore a molecule of oxygen could get at anytliing 

 to burn it, it must needs knock four molecules of nitrogen 

 out of its way and heat tliem up into the bargain, thereby 

 greatly diminishing the energy of combustion all over the 

 globe. It was found, however, that wlien nitrogen did get 

 into coml)ination with other elements it could form very 

 powerful and important substances such as annnonia, its 

 coni]Kjund witli hydrogen, and nitric acid, its conj])ound 

 with oxygen. 



Besides these two gases, there were found in the air 

 others in small quantity but of immense importance, water 



