468 Scientific Intelligence. ' 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On the Influence of Electric Oscillations on Vapors. — It has 

 been pointed out by Kaupfman that when the vapors of various 

 chemical compounds are subjected to the influence of electric 

 oscillatory discharges the results obtained are: (1) the vapor 

 becomes luminous, (2) it is crossed by spark discharges, generally 

 of a green color, or (3) it remains dark, at least until a very high 

 pressure is reached. More than fifty vapors were examined in 

 this way, and the results, while too few to permit of general 

 deductions, yet appear to indicate certain constitutive influences. 

 Thus, for example, the aromatic amines for the most part become 

 luminous and show quite similar appearances, the lacility with 

 which luminosity occurs appearing to be partly dependent on 

 the basic character of the amine ; since compounds which have 

 lost their basic character by substitution, such as nitraniline and 

 tribromaniline, no longer become luminous by the discharge. 

 Cyclic compounds, however, containing nitrogen, do not appear to 

 follow this rule. In the case of hydrocarbons, aliphatic com- 

 pounds and the more simple benzene compounds remain dark until 

 a very high pressure is reached, though most of the hydrocar- 

 bons containing two or more benzene rings readily become lumi- 

 nous. During luminosity, it was noticed that in all cases the 

 vapor acted as a conductor. — Zeltschr. phys. Chem., xxvi, 7 1 9— 

 727, August, 1898. g. f. b. 



2. On the Occlusion of Oxygen and Hydrogen by Platinum 

 black. — In experiments made by Mond, Ramsay and Shields to 

 test the occlusion of oxygen and hydrogen in this way, the plati- 

 num black was saturated with hydrogen, heated at 184° under 

 reduced pressure, then placed in an ice calorimeter and allowed 

 to reabsorb the gas. It was found that 68*8 calories were evolved 

 for every gram of hydrogen occluded. In the opinion of the 

 authors the argument offered by Berthelot in support of the 

 existence of the compounds Pt 30 H 2 and Pt 30 H 3 are not justified by 

 the facts. Moreover they conclude that the difference between 

 palladium and platinum, in their behavior towards hydrogen, as 

 stated by Favre, is due simply to the presence of oxygen in the 

 platinum black. On attempting to remove the oxygen from 

 platinum black, in order to determine its heat of occlusion, it was 

 noticed that reducing agents, while eliminating the oxygen, were 

 themselves occluded and retained obstinately. It was also 

 observed that hydrogen does not remove all the oxygen, but only 

 replaces that at first removed, both gases being simultaneously 

 occluded. On saturating platinum black with hydrogen and 

 exhausting it at 184°, it was found that, on allowing it to come in 

 contact with small quantities of oxygen, the addition of more 

 oxygen beyond a certain point, caused the pressure to increase. 



