Chemistry and Physics. 413 
oxygen bubble was replaced by other bubbles containing less oxygen, 
the tendency inwards of the oxygen was less powerlul ; and when what 
may be called an oxygen vacuum (being a bulb filled with oxygen, ex- 
hausted, and then hermetically sealed) was put up, it simply balanced 
the nitrogen bubble. Oxygen at half an atmosphere was less magnetic 
than that at one atmosphere, but more magnetic than other oxygen at 
one-third of an atmosphere ; and that at one-third surpassed the vacuum. 
In fact, the bubble with its contents was more magnetic in proportion to 
the oxygen it contained. On the other hand, nitrogen showed no differ- 
ence of this kind; whether a bubble contained that gas more or less 
condensed, its power was the same. Other gases (excepting olefiant and 
cyanogen) seemed in this first rough apparatus to be in the same condi- 
ion. ‘The air-pump vacuams of all the gases were alike, including 
that of oxygen. 
Hence the author decides upon the place for zero, and concludes 
that simple space presents that case. When matter is added to space 
termined, he concludes to use the word magnetic as a general term, 
and diamagnetic substances. 
There is no other gas like oxygen; its paramagnetic character is very 
high. A solution of protosulphate of iron in distilled water was pre- 
another case, a glass bubble, containing one-third of a cubic inch of 
oxygen, was opposed to a corresponding bubble having wit 
oxygen vacuum. As soon as the magnetic power was 0D, the oxygen 
passed inwards, and it required a force equal to one-tenth of a grain to 
hold it out at the equidistant position. : 
The author then refers generally to the air as a paramagnetic me- 
ium, because of the oxygen it contains, and in the next, or Twenty- 
sixth Series of Researches, he proposes to enter, afier some preliminary 
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the author to apply for a time the idea of conducting power to the mag- 
 ‘heti ibed, meaning by that phrase the capability 
ing the transmission of the magnetic force 
affected ; and assuming that two bodies are at the.same tim 
magnetic field, and that one displaces the 
asa differential effect of their difference 1n conducting power. ie 
_ Ifa free portion of space be considered with lines of equal magnetic 
force passing across it, they will be stwaight and parallel lines. If a 
2 of paramagnetic matter be placed in such a space, they will 
