344 EXPERIMENTS ON THE RELATION 



sphere blown in its middle, and its other extremity plunged 

 into pure water, in a glass pneumatic cistern. 



When the part of the green glass tube where the turnings 

 lay, was brought to ignition very visible in day-light, it was 

 moved forward with its supporting semi-cylinder of iron, by 

 imperceptible degrees. Thus the salt was exhaled from the 

 bottom., so slowly, that its vapour, in traversing the numerous 

 convolutions of the iron laminae, was almost entirely decompo- 

 sed into its constituent gases. The muriatic acid gas was (as 

 formerly stated) partly condensed into muriate of iron, partly 

 into liquid acid in the bulb, and partly into the water in the 

 glass cistern. 



Of permanent gaseous matter 106 cubic inches were collec- 

 ted, after the whole salt had been sublimed from the bottom of 

 the tube. One hundred cubic inches of these were found by 

 explosion with oxygen in my eudiometer, to consist of 77 hy- 

 drogen -f- 23 azote. Hence the total product of 106 cubic 

 inches was composed of 81.62 hydrogen, and 24.38 azote. 



Now 30 grains of sal ammoniac contain 9.66 gr. of ammo- 

 nia. And since 18.178 gr. of this alkaline gas occupy the vo- 

 lume of 100 cubic inches, but are resolvable into double that 

 volume, or 200 cubic inches of constituent gases; therefore 

 9.66 gr. of ammonia will give by their entire decomposition 

 106.28 cubic inches of gaseous products. Of these, one-fourth 

 according to M. Gay Lussac's theory of volumes, is azote, and 

 three-fourths hydrogen j or 26.57 of the former, and 79.71 of 

 the latter. 



Hence we see that the total bulk of evolved gases, coincides 

 very nearly with the quantity known to exist in the ammonia. 

 The azote, therefore, is not concerned in the production of the 

 water. The deficiency of about two cubic inches of this gas, 

 may be fairly ascribed to a small portion of the salt having 



escaped 



