I 



1814.] On the Composition of Azote. 367 



1. IVater. — An exact knowledge of the composition of water 

 affords the easiest and most correct data for ascertaining the weiglit 

 of an atom of hydrogen, and as it seems generally agreed to be 

 composed of 88*25 oxygen and 11-75 hydrogen, we can imme- 

 diately arrive at its estimation by comparing the weights of the 

 constituents with each other ; hence the weight of an atom of 

 hydrogen is to one of oxygen as 0-13314 to 1. Although this 

 number differs a triHe from that fixed upon by you in pag» A2 of 

 the second volume of your Amials, yet the result above given seems 

 the natural result of the proportions just cited. This number I 

 liave therefore adopted in the foregoing calculations. 



2. Nitric Acid. — That nitric acid should consist of the same 

 proportions of oxygen and hydrogen as water, at first view startles 

 us ; but the surprise will immediately vanish on more minute exa- 

 mination Although hotii consist of the same proportions of oxygen 

 and hydrogen, yet the elementary atoms are arranged in different or- 

 der. Each atom of water is simply composed of two elementary atoms, 

 one of oxygen and one of hydrogen ; while every atom of nitric 

 acid consists of twelve elementary atoms, six of oxygen and six of 

 hydrogen, or of one compound atom of azote and five elementary 

 atoms of oxygen : their arrangement will be six atoms of hydrogen 

 round one of oxygen, forming an atom of the second degree, and 

 five atoms of oxygen again sufrounding these, the whole forming 

 an atom of the tiiird degree, or of three series. This view of tlie 

 subject enables us to conceive more clear ideas of the nature of 

 affinity ; as it will account for the small force with which the 

 oxygen is held in it, and will exhibit sufficient cause why it is 

 always resolved into oxides of azote of a lower degree, or into 

 azote and oxygen, and never into hydrogen and oxygen separately. 

 The proportion of 1 A + 5 O, which 1 had fixed upon as the pro- 

 bable constitution of nitric acid, is precisely the same as that deter- 

 mined by you in the last number of your Annals. It is equal to 

 C H + 6 O. 



By thus considering nitric acid to be formed of an equal number 

 of atoms of oxygen and hydrogen, vvc arrive at its probable consti- 



n o 

 tution as composed of azote and oxygen. Thus as 44*4 : 55-6 :: 



H O H <) Az O 



1175 : 1471 • Then U-75 + 1471 = 26-46, and 88-25 ^ 



o o 



14-71 = 7-^*5'l. Hence 100 parts of nitric acid are composed of 

 2G*46 azote and 7>^'54 oxygen. Now the proportion of azote to 

 oxygen in nitric acid ascertained by the experiments of Berzelius 

 {Aiinnb, ii, 283,) is 26"- 13 azote to 73-57 oxygen — quantities sin- 

 gularly correspondent with those just determined. The calculations 

 of Berzelius, who considers nitric acid to be composed of 11 -7 1 

 nitric and 88-29 oxygen, corrc-pond also ccjually well with tl\os(! 

 I have deduced for the proportions of oxygen and l)ydrogen, and 



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