72 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry axd Physics. 



1. The Oxidation of Paraffine by Means of Oxygen Gas. — 

 Heretofore little success has been attained in the many attempts 

 that have been made to produce directly oxidation products, 

 such as fatty acids and alcohols, from the hydrocarbons of 

 paraffine and similar substances. C. Kelber has recently found, 

 however, that in the presence of certain catalyzers, such as oxides 

 of manganese, oxygen gas brings about such changes with con- 

 siderable rapidity. His most interesting obserYation, howeYer, 

 at which he was astonished, was the fact that oxygen gas, in the 

 absence of any catalyzer, when it is passed in a finely divided con- 

 dition into melted paraffine at a temperature of 140 to 150° C. 

 begins to act after a time, a watery liquid and also a mobile oil 

 distil over into the receiver, while carbon dioxide is another 

 product of the reaction. If the rapidity of the oxidation is not 

 checked either by cooling or by diminishing the stream of oxy- 

 gen, the temperature rises with increasing violence of the reac- 

 tion to above 200°, and the oxidation is finished in 4 or 5 hours. 

 At the time of the publication of this announcement the products 

 of this reaction had not been studied, but they appear to be 

 similar to those produced in the presence of a catalyzer, where 

 there is a yield of 40 to 50% of fatty acids insoluble in water but 

 soluble in petroleum ether, 5% of fatty acids insoluble both in 

 water and in petroleum ether, a small percentage of unsaponi- 

 fiable matter, and also some water-soluble and volatile acids as 

 well as other compounds, some of which are alcohols. The fatty 

 acids insoluble in water give alkali-salts which show a high froth- 

 ing capacity. It seems quite possible that this oxidation process 

 may be of commercial importance. — Berichte, 53, 60. 



h. l. w. 



2. A New Determination of the Value of the Radium-Uran- 

 ium Ratio. — The amount of radium in equilibrium with uranium 

 in minerals containing the latter element is of considerable theo- 

 retical and practical interest. This ratio was first determined 

 by Rutherford and Boltwood as 7-4 X 10~ 7 , but a little later this 

 value was changed to 3-8 X 10~ 7 on account of the fact that an 

 error had been made in regard to the strength of the radium 

 standard solution on account of a partial precipitation of the 

 radium. Still later Boltwood, having made a re-determina- 

 tion of the uranium in the standard uraninite, gave the value 

 as 3-4 X 10 -7 . Afterwards Rutherford, by comparing the 

 previously used radium standard with the International Radium 

 Standard, calculated the ratio to be 3-23 X 10~ 7 . Other 

 investigators have determined the ratio as follows : Hei- 

 mann and Marckwald, 3-328 X 10~ 7 : Becker and Jannasch, 



