18 Professor Bischof s Beasons against 



Professor Daubeny, however, remarks, that the nitrogen 

 proceeding from thesa actions may reach the air not only in 

 a separate condition, but also united with hydrogen in the form 

 of ammonia. It is true, ammonia, especially sal-ammoniac, 

 occurs among volcanic matters in craters or fumaroles, but, in 

 general, in such small quantities as not to be sufficient to ac- 

 count for the huge quantities of nitrogen supposed to be sepa- 

 rated according to the chemical theory. But, even granting 

 all the nitrogen separated from atmospheric air to be united 

 with hydrogen occurring in the focus of a volcano, chemists 

 ought to ask, if a union of these gases can be supposed possi- 

 ble in the direct way 1 It is well known that chemists have 

 hitherto been unable to unite directly these gases, even by 

 letting down a mechanical mixture of nitrogen and hydrogen 

 gas under the sea, to a depth of 540 metres, where the pres- 

 sure is equal to 50 atmospheres. It cannot be doubted that 

 the same laws of combination which take place in our labora- 

 tories also prevail in volcanos. But it may be replied that, 

 for effecting combinations in the focus of a volcano, there are 

 two powerful agents, not presented together in our labora- 

 tories, at least not in such a strong degree, viz., an enormous 

 pressure, and heat. The former of them seems not to favour 

 the combination of nitrogen with hydrogen, as we have above 

 seen ; and as for the latter, it is well known that ammonia is 

 resolved into its elements by heat. Therefore, it is scarcely 

 probable that an enormous compression in the focus of a vol- 

 cano, assisted by a considerable heat, can effect a chemical 

 combination between nitrogen and hydrogen. 



However, the defenders of the chemical theory of volcanos 

 will adduce the known fact that a mechanical mixture of hy- 

 drogen in excess, of oxygen, and of nitrogen, when ignited, 

 produces ammonia, or rather nitrate of ammonia, and that, ac- 

 cording to their theory, these substances ought to be present 

 in the focus of a volcano. Supposing, for a moment, the for- 

 mation of this salt, it is obvious that it would instantly be de- 

 composed by heat into water and the protoxide of nitrogen. 

 But, they will ask, how can you explain the occurrence of sal- 

 ammoniac among the products of volcanic action, unless by 

 the combination of the nitrogen with hydrogen ? In reply- 



