owes to the learned President of the Royal Society.
One obvious consequence of fuller demonstration of this difficult subject is, that we may hope to find in it a settlement of the long vexed question about contagion; and that, together with that settlement, we may look for the abolition of many hurtful and of all needless regulations. Whilst no one disputes the evidence of many facts pointing to the theory of infection, no one, even in the present state of knowledge, can fail to perceive an imperative agent guiding the path of disease, and dominating both its progress and its degree of virulence. The final law, when once revealed, will of course reconcile all those apparent anomalies which are now perplexing to our partial knowledge. It will teach us better principles on which to work in our attempts to devise sanitary arrangements; and, whilst we shall still rejoice that measures for purification, disinfection, cleanliness, and an adequate supply of pure water and wholesome food, are unremittingly adopted, we shall be spared those misgivings which
