Point counting, density measurement

An interesting historical application of the Boltzmann equation involves examination of the number density of very small spherical globules of latex suspended in water. The particles are dishibuted in the potential gradient of the gravitational field. If an arbitrary point in the suspension is selected, the number of particles N at height h pm (1 pm= 10 m) above the reference point can be counted with a magnifying lens. In one series of measurements, the number of particles per unit volume of the suspension as a function of h was as shown in Table 3-3. 

The liquid density, a measure of molecular packing and molar volume, has been modeled by Kier and HalF. For normal alkanes the density is inversely proportional to the count of carbon atoms. Hence in this model, an inverse x index is used. When dl is plotted against set of convergent lines is obtained for the various classes of branched alkane isomers, such as 3-methyl, 2-methyl, 2,3-dimethyl, etc. The focus of these convergent lines is a point on the density axis, 0.83. ... 

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