Chemistry and Physics. 143 
found to be, 98°43° and 98°42° in two. portions. On analysis it 
ve 83°81 carbon, 16°05 hydrogen, while heptane C,H,, requires 
114111. The specific gravity at this temperature is 0°61393 and 
its specific volume is 162-54, that calculated from Kopp’s values _ 
being 165. Its refractive index was found to be 13879 at 17°6° 
—1, 
£ > Fs 0°565; 
and its molecular refractive energy is 56°4, the value from 
for the sodium line. The specific refractive energy 
capl ty. 1s KnOV 
liquid. idee believes that this heptane is probably isomeric with 
that obtained from petroleum and probably identical with that 
fr ic acid.— J. Chem. S 
ma 
cussion of the different ways by which colors are produced ; the 
theory of color (that of Young); mixture of colors; comple- 
— colors; and an account of the many effects prod uced by 
