The existence of hydrates in solution

Assuming that the amount of such a definite compound is proportional to the concentration of the solution, the rate of change of, say, the density, s, with change of concentration, p, will be a linear function of p, in other words, ds/dp will be represented by the equation for a straight line. From the differentiation of (1), we obtain, 

But after all we are only working with empirical formulae, and no juggling with feeble empirical expressions, and no appeal to the mysteries of elementary mathematics can legitimately make experimental results any more really discontinuous than they themselves are able to declare themselves to be when properly plotted .1 

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Few years later (1865 - 1887), D. Mendeleev proposed his theories regarding chemical solutions. According to Mendeleev, dissolution processes are chemical interactions between solvent and solute particles upon salt dissolution in water, dissolved hydrates are generated. Later, in 1889, Mendeleev criticized Arrhenius achievements and this last, for himself, refuse to accept the existence of hydrates in solutions. Actually, both theories are complementary and the existence of hydrates was, then, pointed out by A. Kablukov, in 1891 [2]. 

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