24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 54 



These experiments we may arbitrarily assign equal weight with two 

 in Dittmar and Henderson's later series, when the resnlt becomes 15.881, 

 ±.0132, the value to be accepted. Lediic states that his copper oxide, 

 which was reduced at as low a temperature as possible, was prepared 

 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 Eegnault. The globes were contained in an artificial "cnve," 

 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 burned 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 apparatus, from which the unburned residue could be withdrawn for 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. Eubber joints were avoided in the 

 construction of the apparatus, and the connections were continuous 

 throuofhout. The weights and derived ratios are as follows: 



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

 Edward W. Morley. Smithsonian Contributions to Knowledge, 29, 1895, 4to, xi + 117 pp., 40 cuts. 

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

 densities); also note in Am. Chem. Journ., 17, 39G. Preliminary notice in Proc. Amer. Asso- 

 ciation, 1891, p. 185. See also a discussion by Morley of all the earlier determinations, in the 

 Western Reserve University Bulletin, for April, 1895. 



