240 HYDROGENATED COMPOUNDS OF NITROGEN. 



Moreover, these figures vary considerably, according to the 

 conditions of the experiments, as might be expected. It would 

 be easy to reduce them still further, and perhaps even to annul 

 them altogether, by taking precautions to diminish the elevation 

 of temperature developed upon the first contact of the chlorine 

 with the ammonia, a diminution which was not attempted by 

 any special contrivance. As they are, these numbers are in 

 relation to the same conditions in the calorimetric measure- 

 ments, and they are sufficient to establish the incomplete 

 character of the reaction. 



The liquids thus subjected to the action of chlorine contain 

 ammonium hypochlorite, a compound previously mentioned by 

 Balard and by Soubeyran, who had prepared it, the one with 

 hypochlorous acid,, the other with chloride of lime. The 

 presence of hypochlorous acid may, in fact, be manifested in 

 it. Perhaps there are also some chloro-substitution bases, inter- 

 mediate between nitrogen chloride and ammonia. 



The above liquids are in an unstable condition; they are 

 continually giving off nitrogen. We have merely to pour 

 them off into another vessel or stir them with a rod in order 

 to make them pass into the gaseous form. They are well 

 adapted to the repetition of Gernez's elegant experiments. 

 Even after a day or two, the slow liberation of the nitrogen 

 continues. 



The author tried whether he could obtain at one stroke the 

 nitrogen in solution, by adding to the liquid an excess of 

 hydrochloric acid. The liquid, which had at first furnished 

 32 cms. of nitrogen, gave off upon this second operation 

 38*6 cms. ; in all, 70'6 cms. instead of 81 cms. This last deficit 

 results either from the solution of a small quantity of nitrogen, 

 owing to the great volume of the final liquid, or to some 

 quantity of chlorine being employed in a secondary reaction, 

 such as the formation of a little chlorate or perchlorate. How- 

 ever this may be, the facts above mentioned show the causes of 

 the errors of the first experimentalists. The action of chlorine 

 upon ammonia could not, at any rate under the conditions 

 with which they worked, be employed for measuring the heat 

 of formation of this substance. 



The action of the hypobromites would seem to be preferable, 

 judging from the measurement of the volume of nitrogen 

 liberated. This reaction, however, was not wholly satisfactory. 

 The object in view was arrived at by quite another method, 

 which is very simple and apparently faultless, as regards the 

 completeness of the reaction, the direct combustion of the 

 ammoniacal gas was effected by means of free oxygen. 



5. Combustion of ammonia. The combustion of ammoniacal 

 gas in free oxygen is effected with the same facility as that of 

 hydrogen. It may easily be performed in the glass combustion 



