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THE BEGINNINGS OE LIFE. 



85 



hydrogen^ oxygen^ and nitrogen show the least atomic 

 cohesion of. all elements."^ And while oxygen displays, 

 alike* in the range and intensity of its afSnities, a 

 chemical energy exceeding that of any other substance 



F ■ 



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(unless fluorine be considered an exception), nitrogen 

 displays the greatest chemical inactivity 1. Now on 

 calling to mind one of the general truths arrived at 



tj and musth 

 lobility of 



Hence Mr. S- 



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1 between tki 

 ief organic k 

 jndergotec 



when analyzing the process of. Evolution in general, 

 the probable significance of this double difference will 

 be seen. It was shown (*^*^ First Principles/^ § 123) that, 



easily se- 

 parated by incident forces than like units are- — that 

 an incident force falling on units that are but little 



other things equal, unlike units are more 



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^ Hence its compounds are generally most unstable. * Here it will 

 we call deve;: be well to note, as having a bearing on what is to follow, how charac- 

 ^,« Tt-ViJfU- teristic of most nitrogenous compounds is this special instability. In 



all the familiar cases of sudden and violent decomposition, the change is 



lat is ncrcff due to the presence of nitrogen. The explosion of gunpowder results 



q-i fQUff'f from the readiness with which nitrogen contained in the nitrate of 



potash yields up the oxygen combined with it. The explosion of gun- 

 !:0lly COmpt^^ cotton, which also contains nitric acid, is a substantially parallel phenq- 



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tithese? 



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menon. The various fulminating salts are all formed by the union with 



metals of a certain nitrogenous acid called fulminic acid ; which is so 



unstable that it cannot be obtained in a separate state. Explosiveness 



^r fliein^ ^s ^ property of nitro-mannite, and also of nitro-glycerine. Iodide of 



nitrogen detonates on the slightest touch, and often without any assign- 



asse^ ^■ 



.St ifl 



cd CO ntr^-^ able cause. Percussion produces detonation in sulphide of nitrogen. 



highest 



degree 



temp 

 \ 



a 



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And the body which explodes with the most tremendous violence of any 

 that is known, is the chloride of nitrogen. Thus these easy and rapid 

 decompositions, due to the chemical indifference of nitrogen, are charac- 

 teristic. When we come hereafter to observe the part which nitrogen 

 f|( plays in organic actions, we shall see the significance of this .extreme 

 readiness shown by its compounds to undergo change.'— Spencer* loc. 



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cit. p. 8, 



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