NEW METHOD OF ANALYSING AMMONIA, 361 



From the average of a great number of experiments on Proportion of 

 the decomposition of ammonia by electricity, I was for Permanent gas 



i i , ,. , , , , , obtained froia 



some time led to believe, that you had rather understated ammonia, 

 the proportiou of permanent gasses obtainable from it by 

 this process, (viz. 10S measures of permanent gas, from 60 

 of ammonia, or 180 from 100). For the most part, I had 

 found the bulk of ammonia to bo doubled by decomposition, 

 even when the gas was previously dried with extreme care, 

 In one instance, a small bit of dried potash was left in the 

 tube, along with the ammonia, during electrization, with 

 the view of its absorbing water, which I supposed, at that 

 time, to be generated by the process. In this case, 59 mea- 

 sures, (each s= 10 grains of mercury) became 115. The 

 following table shows the expansion of various quantities of 

 ammonia, 

 Exp. 



1. 60 measures of ammonia, gave permanent gas 112 



2. 60 - - - - - i20 nearJ y <JoubI» 



3. 59 (potash being left in the tube) - . 115 



4. 55 - „ - - - 115 



5. 75 (under the pressure af half an atmosphere) 150 

 5. 65 ----- 130 



7. 65 - - - - - 130 



8. 53 (one of the conductors being of steel wire) 105 



492 978 



Judrogcn by electrization, as gas which had not been thus exposed. 

 I was not however aware, at that time, of the extreme caution 

 necessary in experiments of this kind ; and was satisfied with trans- 

 ferring the acid gas from a large vessel, in which it had been dried, 

 into the electrizing tube, a mode of proceeding which J now find 

 to be quite inadmissible. The action of muriate of lime, which has 

 undergone fusion, on muriatic acid gas, is rendered very sensible, 

 when considerable quantities are used, by the evolution of much 

 heat, and by a diminution of the volume of the gas. Ammonia, 

 also, is contracted in bulk by dry caustic potalh. Muriate of lime 

 cannot be employed for its desiccation, since this substance rapidly 

 absorbs the alkaline gas, even when the gas has been previously 

 exposed to quick-lime. In this case, the ammonia attracts a por- 

 tion of muriatic acid from the earthy salt, agreeably to the law of 

 affinity, which has been, so ably illustrated by Berthollet. 



and 



