A curious interest began to engage him about this time. The years following 1739 were years of suffering in the Irish diocese. It was a time of famine followed by widespread disease. His correspondence is full of allusions to this. It had consequences of lasting importance. Surrounded by disease, he pondered remedies. Experience in Rhode Island and among American Indians suggested the healing properties of tar. Further experiments in tar, combined with meditation and much curious reading, deepened and expanded his metaphysical philosophy. Tar seemed to grow under his experiments, and in his thoughts, into a Panacea for giving health to the organism on which living mind in man is meanwhile dependent. This natural dependence of health upon tar introduced thoughts of the interdependence of all things, and then of the _immediate_ dependence of all in nature upon Omnipresent and Omnipotent Mind. The living Mind that underlies the phenomena of the universe began to be conceived under a new light. Since his return to the life of thought in Rhode Island, he had been immersed in Platonic and Neoplatonic literature, and in books of mystical Divinity, encouraged perhaps by the mystical disposition attributed to his wife. An eccentric ingenuity connected the scientific experiments and prescriptions with the Idealism of Plato and Plotinus. The natural law according to which tar-water was universally restorative set his mind to work about the immanence of living Mind. He mused about a medicine thus universally beneficial, and the thought occurred that it must be naturally charged with ’pure invisible fire, the most subtle and elastic of bodies, and the vital element in the universe’; and water might be the natural cause which enables this elementary fire to be drawn out of tar and transferred to vegetable and animal organisms. But the vital fire could be only a natural cause; which in truth is no efficient cause at all, but only a sign of divine efficiency transmitted through the world of sense: the true cause of this and all other natural effects must be the immanent Mind or Reason in which we all participate; for in God we live and move and have our being.