"The contemplation," he writes, "of the wonderful processes which constitute life,--the exquisite mechanism (as far as that mechanism can be traced) by which they are performed--the surprising adjustments and harmonies by which, in a creature like man, such diverse and opposite actions are brought into relation with each other and made to work in subserviency and co-operation;--and the divine object of all--the communication of sensation and intelligence as the inlets and instruments of happiness--afforded the highest satisfaction to my mind. But this beautiful world, into whose workings my eye now searched, presented itself to my view as a demonstration that the Creative Power is infinite in goodness, and seemed to afford, as if from the essential elements and profoundest depths of nature, a proof of His love." This book came to be a help to many of all classes and creeds, and passed through several editions. He was often urged to reprint it in later life, but held it back, wishing to modify it slightly. Not that his opinion of its main principles had altered in the least degree, but that he thought he had passed too lightly over the sea of misery and crime that there is in the world; he thought there was rather too much of the bright hopefulness of youth about it. Sorrow he had known, certainly, in the loss of his wife; but the sorrow that comes from the loss of one who was noble and good, and who has been taken from us by death, is of quite a different kind from that which comes from a closer acquaintance with the mass of sin and misery which exists. He did not change his view that, even this, rightly understood, is consistent with the divine benevolence; but he wished to recognise more fully its existence, and to enter more largely into the subject. Having completed his medical studies and obtained his degree, the young physician determined to take a practice in Yeovil. The following extract from a letter, dated August 5, 1816, addressed by him to a friend in Rome,[3] shows with what views as to his future profession he quitted Scotland. "I leave Edinburgh this week," he writes; "I leave it with much regret, for I have found friends here whom I shall ever remember with respect, affection, and gratitude. I go to Yeovil, a little town in the west of England, where it is my intention to take charge of a congregation and at the same time to practise medicine. This double capacity of physician to body and soul does not appear to me to be incompatible, but how the plan will succeed can be determined only by the test of experience. "My expectations are not very sanguine, but neither are my desires ambitious." "The test of experience" proved that he was admirably qualified for the double office he had taken upon himself, and for some years he pursued faithfully the plan he had made.