222 On the Quantity of Carlon in Carbonic Acid, 



21 480) 2 1-00 (0-043 60* 



•68 add for temp. 16 44 



21-68 0-688 add for temp. l6difF, 



Correction lor pressure. 

 30 : 29-86 : : 21-68 : 21-58. 



The volume therefore at mean temperature and pressure 

 would have been 21*58 cubic inches. 



21-58 : 10-2 : : 100 : 47-26 

 Consequently 100 cubic inches of carbonic acid gas at" 

 inean temperature and pressure weigh 47*26 grains. 



We next tried oxygen gas from the hyperoxygenised 

 muriate of potash made over mercury, and which, by the 

 eudiometer, left only a residuum' of 2 parts in 100. Th^ 

 glass globe exhausted as before, and weighed, was, screwed 

 on to the glass receiver of the mercurial gasometer contain- 

 ing oxygen, and 21 cubic inches entered, by which it in- 

 creased in weight 7*3 grains. This experiment was repeat- 

 ed with exactly the same result. The thermometer and ba- 

 rometer remaining the same, we take the volume as before 

 corrected. 



21-58 cubic inches. 

 21-58 : 7-3 : : 100 : 33-82. 

 Then 100 cubic inches of oxygen gas at mean temperature 

 and pressure weigh 33-82 grains. After these experiments 

 we examined Davy's researches on nitrous oxide, and had 

 the satisfaction to find that his estimate, both of carbonic 

 acid and oxygen gases, agreed almost exactly with ours. 



The next point was to ascertain whether lime-water 

 would take the whole of the carbonic acid gas from a mix- 

 ture with oxygen, or common air j we therefore mixed a 

 known quantity of carbonic acid gas with a certain quantity 

 of common air, and on trying it with owr eudiometer and 

 lime-water, the whole of the carbonic acid gas was in a 

 short time absorbed. We also found, that though the solu- 

 tion of green sulphate, saturated with nitrous gas, would not 

 take up the whole of the carbonic acid gas, yet the simple 



greeii 



