24 



SCIENCE 



[N. S. Vol. L. No. 1279 



increases by two degrees in six or seven hours. 

 They are very marked when a door opening 

 into the hallway is opened for four or five 

 minutes, allowing warmer air to enter the 

 room. The entrance door used when this work 

 is being done is in an adjoining room. When 

 a window is raised for a few minutes, allowing 

 colder air to enter, a sudden decrease in the 

 scale reading results. The convection effect 

 increases as the rate of change of temperature 

 increases. 



, When the suspended masses have been posi- 

 tively charged, and the large masses have been 

 connected with the lightning rod marked ef- 

 fects have been observed on clear days when 

 there was little or no wind. Sometimes the 

 effect was to eliminate convection effects. In 

 all cases there was an apparent decrease in 

 gravitational attraction. The maximum de- 

 crease was usually in the afternoon at about 

 three or four o'clock. The decrease varied 

 from twenty-five to near two hundred per cent. 

 In other words, gravitational attraction was 

 apparently converted into a repulsion. 



These results seem to indicate that there is a 

 daily variation in the electrical potential of 

 the earth. The atmosphere, ionized by solar 

 radiation, acts inductively upon that part of 

 the earth which is exposed to sunlight. Light- 

 ning flashes from cloud to cloud or from clouds 

 to earth furnish abundant evidence that there 

 are also local variations in the potential of the 

 earth. There is no reason why we should not 

 continue to assume the potential of the earth 

 to be zero, as we assume the level of the ocean 

 to be zero in altitude, but there is evidence 

 that there is a condition of matter such that its 

 electrical potential may be defined as zero ab- 

 solute. It is the condition or potential of two 

 masses having a like potential due to charges 

 upon them when their gravitational attraction 

 for each other is a maximum. 



It seems very probable that the free ter- 

 minal of a machine having the other terminal 

 grounded in a pond of water, may be at times, 

 nearer to a potential zero absolute, than the 

 grounded terminal, when the machine is in 

 active operation. This would fully account for 

 different results obtained when the electrical 



machine is used in the electrification of the 

 large masses. These results appear to furn- 

 ish a complete explanation of the phenomenon 

 known as St. Elmo's fire. 



Francis E. Nipher 

 Washington IJniveesity 



THE BUFFALO MEETING OF THE 

 AMERICAN CHEMICAL SO- 

 CIETY. IV 



DIVISION OP PHYSICAL AND INORGANIC CHEMISTRY 



W. E. Henderson, Chairman 

 W. A. Patrick, Secretary 



Action of perchloric acid on metals and non- 

 metals: H. H. WiLLAKD and A. H. Huisken. 



Perchloric acid as am, oxidizing agent in the de- 

 termination of chromium and vanadium: H. H. 

 WrLLARD and W. E. Cake. 



Perchloric acid as a dehydrating agent in the 

 determinination of silica: H. H. Willaed and W. 

 E. Cake. 



The arrangement of electrons in atoms and 

 molecules: Irving Langmtjik. Starting from 

 Eutherf ord 's and Lewis' theory and from chem- 

 ical data, a theory of atomic and molecular struc- 

 ture is developed in which the electrons are sym- 

 metrically arranged about the nucleus in concen- 

 tric shells. From some simple postulates the 

 broad features of the physical and chemical prop- 

 erties of all the elements (including eighth group 

 and rare earths) are derived. There follows a 

 new and rational theory of valency called the octet 

 theory, identical with the ordinary theory for or- 

 ganic compounds and for inorganic compounds 

 giving Werne's theory as a special case. The 

 theory also explains the magnetic properties of 

 the elements. 



Preferential catalysis and the purification of 

 hydrogen: H. S. Taylor. 



New measurements on the direct synthesis of 

 ammonia (lantern) : L. H. Adams. 



Application of the thermionic amplifier to con- 

 ductivity measurements (lantern) : L. H. Adams 

 and E. E. Hall. 



Eleotrometrio titration's, with special reference 

 to the determination of ferrous and ferric iron 

 (lantern) : J. C. Hostetteb and H. S. Egberts. 

 Conditions are given under which very small, as 

 well as large, amounts of ferrous and ferric iron 

 can be readOy determined. Ferrous iron is titrated 

 directly with potassium dichromate (0.002 N to 

 0.10 N) following the change in potential against 



