Minutes of Proceedings. 
xvii 
This paper gives some account of observations taken at various places 
in South Africa in order to find the relation v^hich exists between the 
atmospheric potential gradient and the altitude of the places of observation. 
Observations were taken between Lourenco Marques and Durban, via 
Johannesburg, passing thus from sea-level to sea-level over a considerable 
stretch of country in which the altitudes rose to nearly 7,000 feet. A Wilson 
pattern electrometer was used, the collecting-plate being coated with 
radium. The electroscope had previously been calibrated by a number of 
storage cells, and potentials up to 500 volts could be measured. 
The general result is that there is a great change in the value of the 
potential gradient with the altitude, the extreme value at the highest point 
(6,500 feet) being not more than one-eighth of that at sea-level. Similar 
differences having been observed on previous occasions at other places, led 
to the investigations being conducted. The maximum values were about 
500 volts per metre at Lourenco Marques and Durban, and 58 volts at 
Belfast, 6,500 feet above sea-level, and at places in between values were 
obtained which showed that the greater the altitude the smaller the 
potential gradient. 
An exception to this rule was seen at Johannesburg, where the 
potential gradient was very variable and changed signs at different points 
in the neighbourhood. These variations were traced to the clouds of 
steam, and especially of dust, proceeding from the mine heaps. Steam 
has the effect of increasing the positive gradient, while dust lowers it. 
To the north of Johannesburg there was a normal positive gradient of 
52 volts per metre, whilst at the Observatory, just on the edge of the town, 
the value was 1 60 ; in the town itself the values varied from 0 to 120, 
whilst at the south end, and to leeward of a mine, from which clouds of 
dust were rising, the potential was negative, and reached a value of 
400 volts per metre. The influence of the mine gave a negative gradient 
of more than 100 volts at a distance of a mile. 
The effects due to dust are much more persistent than those due 
to steam. 
" Eespiration and Cell Energy," by Horace A. Wager. 
The theory that the energy required in all organic life is derived either 
directly or indirectly from the sun is disproved. Energy cannot be stored 
away to be drawn upon when required. 
Thus coal does not contain a supply of directly available energy. Its 
energy is only available when oxygen is available, and so it would be just 
as correct to say that the energy comes from the oxygen as from the coal. 
Similarly starch does not contain a store of energy, but energy from some 
other source is required to decompose it before its constituents can be 
used in the metabolism of the cell. The first energy available, say, in a 
germinating cell, probably comes from some synthetic process set up by 
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