OXYGEN. 21 



following Dumas' method with slight modifications, gives the results of 

 only two experiments, as follows : 



Wt. Water. Wt. O. At. Wt. O. 



22.1632 19.6844 15.882 



19.7403 17.5323 15-880 



Mean, 15.881 



These experiments we may arbitrarily assign equal weight with two 

 in Dittmar and Henderson's later series, when the result becomes 

 15.881, =b .0132, the value to be accepted. Leduc states that his copper 

 oxide, which was reduced at as low a temperature as possible, was pre- 

 pared by heating clippings of electrolytic copper in a stream of oxygen. 



To E. W. Morley * we owe the first complete quantitative syntheses of 

 water, in which both gases were weighed separately, and afterwards in 

 combination. The hydrogen was weighed in palladium, as was done by 

 Keiser, and the oxygen was weighed in compensated globes, after the 

 manner of Regnault. The globes were contained in an artificial " cave," 

 to protect them from moisture and from changes of temperature; being 

 so arranged that they could be weighed by the method of reversals with- 

 out opening either the " cave " or the balance case. For each weighing 

 of hydrogen about 600 grammes of palladium were employed. After 

 weighing, the gases were burnt by means of electric sparks in a suitable 

 apparatus, from which the unburned residue could be withdrawn for 

 examination. Finally, the apparatus containing the water produced was 

 closed by fusion and also weighed. Rubber joints were avoided in the 

 construction of the apparatus, and the connections were continuous 

 throughout. The weights are as follows : 



H taken O taken. H^O formed. 



* " On the Density of Oxygen and Hydrogen, and on the Ratio of their Atomic Weights," by 

 Edward W. Morley. Smithsonian Contributions to Knowledge, 1895, 4to, xi + .117 pp., 40 cuts. 

 Abstract in Am. Chem. Journ., 17, 267 (gravimetric), and Ztschr. Phys. Chem., 17, 87 (gaseous densi- 

 ties) ; also note in Am. Chem. Journ., 17, 396. Preliminary notice in Proc. Amer. Association, 

 1891, p. 185. 



