only exact branch of science—mathematical physics—and Van't Hoff showed that we can deal with solutions in the same manner.
This raises the further question why is it so important to have a satisfactory theory as to the nature of solutions? A moment's thought will furnish the answer. The whole science of chemistry is a branch of the science of solutions. Similarly, the biological sciences are dependent upon solution for their existence, and geology, in dealing both with the sedimentary and the igneous rocks, is vitally concerned with solution in the broader sense of that term. There are, then, few branches of natural science that are not dependent upon solution for their existence.
Van't Hoff made a number of other contributions to science, second in importance only to those named above. He told us what is meant by "Solid Solutions." His last work was an experimental study of the conditions under which the great salt beds at Stassfurth were laid down from a desiccating inland sea.
Van't Hoff published a number of books on physical chemistry but it would lead us too far here to discuss them in any detail.
The writer knew Van't Hoff in the relation of student to teacher. He was one of the most modest, frank, honest and unselfish of men. He lived to see his work properly understood and appreciated. He was elected a member of most of the learned societies and academies in the world. He was awarded the first Nobel prize in chemistry in 1901.
The name of Van't Hoff will undoubtedly go down in the history of science along with those of the very greatest—with Maxwell and Sir J. J. Thomson; with Laplace and Pasteur, and with Helmholtz and Lorentz.