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tions and experiments, and often in person attended his demonstrations. It was to the king that Harvey dedicated his immortal treatise "De Motu Cordis" in poetical terms of comparison between the heart and body and the soverign and body politic.
"The heart of animals is the foundation of their life, the sovereign of everything within them, the sun of their microcosm, that upon which all growth depends, from which all power proceeds."
It would be as difficult to understand vital functions, the conditions of health and disease, apart from the circulation of the blood, as it would be to explain the movements of the heavenly bodies without the law of gravitation. Harvey, as has been truly said, is the Newton of physiology. His " Exercitatio " is such a complete and closely reasoned proof of the circulation, that in the 274 years that have elapsed since its publication nothing of material consequence has been added to the cogency of his arguments ; and his demonstration of the movement of the blood in a circle is a model of exposition which cannot be surpassed by any lecturer on physiology at the present day. Harvey's work deals essentially with the
