I'Airr I \'.— SYNTHESIS of water from wkkjiikd quantitiks 



OK HYDROGEN AND oXYGEN. 



1 . INTKODUCriON. 



In tlic following pages :ire described .some ex])eiiiiieiits in w liicli a (luantity <>f 

 iiytliogeii was weighed while absorbed in palladinni, a (|uantity of oxygen was 

 weighed in a gUibe, the two were combined, and the water produced was weighed. 



Tlie two gases were bi-ought together at two platinum jets enclosed in a small 

 flass apparatus, which was weighed while exhausted, where they were made to 

 combine. ^Vhen the combustion was ended, the gas remaining in this combustion 

 apparatus and the connecting tul)es was extracted with a Toepler air pump, 

 measured, and analyzed. The combustion tul)e, the globe which had contained 

 oxygen, and the i)alladiuni tube were weighed again. From the amounts of oxygen 

 and hydrogen extracted were subtracted the amounts of the gases found in the 

 analysis ; the remainders were the ([uantities combined in the combustion appai-atus, 

 from which the atomic weight of oxygen was found. The amount of water pro- 

 duced was measured by the gain in weight of the combustion apparatus : di\ i«ling 

 this by the amount of hydrogen used, the molecular weight of water was known, 

 and so a second value for the atomic weight of oxygen was obtained. 



The volume of hydrogen used in most of the experiments was forty-two or 

 forty-three litres ; the amount of water produced was about thirty-four granuues in 

 each experiment ; twelve successful experiments were made. The amount of gas 

 left unburned and therefore measured in the eudiometer varied from a sixdiun- 

 dii-dth to a ten-thousandth of the quantity concerned. 



2.— PRonrcTioN axd weiouinc of oxyckx. 



The oxygen used in all the experiments of this series was produced l)y heating 

 potassium chlorate ; the apparatus used is shown in Fig. 7, page L'O; the manipu- 

 lation here was precisely the same as in the other experiments. In fact, often the 

 same cpiantitv of oxvtren served for a determination of density and for a synthesis 



