204 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



slightly acid. The results are accurate. The author has in- 

 geniously applied these methods to the rapid analysis of al- 

 loys. 



Schiitzenberger has announced the discovery of an allo- 

 tropic condition of metallic copper, obtained by electrolysis 

 of a solution of about ten per cent, of copper acetate, pre- 

 viously boiled, with two Bunsen or three Daniell cells, the 

 negative platinum plate being placed parallel to the larger 

 positive copper electrode, and three or four centimeters from 

 it. The allotropic copper is then deposited on the platinum 

 as a brittle metal in rugose plates of an aspect resembling 

 bronze. Its specific gravity is from 8 to 8.2, that of ordi- 

 nary copper being 6.9. The moist plates quickly oxidize on 

 the surface in ordinary air. Allotropic copper is changed to 

 ordinary copper by heat or by prolonged contact with dilute 

 sulphuric acid. 



Dumas has called the attention of the French Academy to 

 the presence of oxygen in metallic silver, and has shown that 

 where silver has been used, in the determination of atomic 

 weights, and, after careful purification, has been converted 

 into minute grains after fusion in presence of borax, nitre, 

 and. air, it is liable to absorb oxygen in amounts varying 

 from 50 to 200 cubic centimeters per kilogram. This may 

 cause a notable error. 



Von Meyer has put to the test the theory of De la Rive, 

 that the so-called catalytic action of platinum is due to the 

 formation of a superficial layer of oxide, which is subsequent- 

 ly reduced, and so on alternately, by examining the action of 

 platinous oxide, platinic oxide, and platinic hydrate upon 

 mixtures of hydrogen and carbonous oxide. He finds that 

 these gases are both oxidized at the expense of the oxygen 

 in the oxide of platinum, the proportion of hydrogen being 

 much the larger. Upon a mixture of hydrogen, oxygen, and 

 carbonous oxide the action of the platinum is directly the 

 reverse, the carbonous oxide being burned in largest propor- 

 tion. The author concludes from these experiments that the 

 theory of De la Rive cannot be admitted. 



ORGANIC. 



Cloez has studied the hydrocarbons which are formed dur- 

 ing the action of acids upon spiegeleisen, and has found that 



