THE NITROGEIS^ BODIES OF MODERX CHEMISTRY. 



A LECTURE BY PROFESSOR KLETZIXSKY. 

 Delivered December 15, Id/O, 



[Translated from Aus der Natur for the Smitlisonian Institution.] 



I liave tlie honor to direct your attention this morning to a group 

 of compound bodies which are of the highest importance, whether we 

 consider them from a theoretrical or a practical point of view. They are 

 all the artificial products of the laboratory, and while the study of them 

 has led to the most interesting views of the constitution of matter, some 

 of them have found a widely-extended industrial application, and others 

 give promise of a brilliant future. They are what is called the nitrogen 

 compounds of modern chemistry : 



Volume substitution is now accepted as the ruling principle of chemi- 

 cal combinations. All substances may be considered as combining in 

 certain definite volumes, and the unit adopted by science in this respect 

 is hydrogen. This atom, which in respect to weight and volume is the 

 chemical standard, we denote as unity, and all other atoms which enter 

 into the composition of bodies, and which require the same space as the 

 atom of hydrogen, can be substituted in the place of this unit. 



Chemists have succeeded in substituting for the hydrogen in organic 

 substances radicals of hyponitric acid; that radical which is denoted by 

 the formula NO2. 



This radical called nifri/l, whose introduction into organic chemistry 

 led to the conception of the nitrogen compomids, is formed when we 

 unite one equivalent, of nitrogen having a combining power of 3 with 

 the weight 14, and two atoms of oxygen which is bivalent, that is, 

 having a combining power of 2 with the weight 16. This body is 

 therefore represented by the formula '"^"O-,, in which the dashes 

 ('" ") represent the combining volumes. Since the nitrogen is trivalent 

 and the oxygen bivalent, and since there are two atoms of oxygen the 

 combining power of which is four, there evidently remains one unappro- 

 priated equivalent volume; and this free equivalent volume determines 

 the equivalence of the radical. On this ground we designate this radical 

 as univalent, or having a combining power of one ; and as such it can 

 be in all cases substituted for the hydrogen monad. 



Now, if this substitutiou of nitryl for hydrogen in organic bodies be 

 extended as far as the actual relations admit, w^e arrive at the formation 

 of the nitrogen compounds. For a complete exposition of our subject 



