CONSTITUTION AND TEMPERATURE ON MAGNETIC SUSCEPTIBILITY. 
125 
as fig. 9g shows, appeared to be less abrupt than usual. # The melting point, if it 
corresponds to the beginning of the dip, is at —54 C. The middle of the dip is at 
a temperature —45° C., which is very nearly equal to the value of the melting point 
( — 43° C.) obtained by other methods. The value of Sy/y * s 5 per cent. 
Benzoyl Chloride. 
n/° 
xyUci 
\/ 
This substance showed a departure from the general rule that for benzene compounds 
the liquid state is more diamagnetic than the crystalline state. Five experiments 
have been made with this substance and two of the curves are shown in fig. 10, 
Curve I. The liquid, which is oily, is seen to be less diamagnetic than the crystals 
by an amount 5 per cent, of the value of y. Taking the point where the decrease of 
y begins, as the temperature of fusion, we deduce —3° C. for the melting point. 
Other methods give — 1°'0 C. 
This substance will be considered later in conjunction with several other compounds 
showing similar properties. 
Benzaldehyde. 
The first experiment made on this substance showed that it possessed the hitherto 
unique property of constancy of the magnetic susceptibility through the normal fusion 
point down to the temperature —150° C., as shown by the curve ABC (fig. 10, Curve II). 
But on taking away the metal cylinder (used to preserve a uniform temperature over 
This may be an effect of too rapid heating of the enclosure combined with low conductivity of the 
substance. 
