Hutton was in many respects the reverse of Black. He was a dweller out of doors, a man of strong vitality and high spirits, careless of dress and appearance, setting little store by the world's prejudices or fashions, and speaking the broadest Scotch, but overflowing with views and speculations and fun, and with a certain originality of expression, often very piquant. Every face brightened, says Playfair, when Hutton entered a room. He had been bred a doctor, though he never practised, but, devoting himself to agriculture, had been for years one of the leading improvers of the Border counties, and is said, indeed, to have been the first man in Scotland to plough with a pair of horses and no driver, the old eight-ox plough being then in universal use. Between his early chemical studies and his later agricultural pursuits, his curiosity was deeply aroused as he walked about the fields and dales, not merely concerning the composition but the origin of the soils and rocks and minerals that lay in the crust of the globe, and he never ceased examining and speculating till he completed his theory of the earth which became a new starting-point for all subsequent geological research. He was a bold investigator, and Playfair distinguishes him finely in this respect from Black by remarking that "Dr. Black hated nothing so much as error, and Dr. Hutton nothing so much as ignorance. The one was always afraid of going beyond the truth, and the other of not reaching it." He went little into general society, but Playfair says that in the more private circles which he preferred he was the most delightful of companions. The conversation of the club was often, as was to be expected from its composition, scientific, but Professor Playfair says it was always free, and never didactic or disputatious, and that "as the club was much the resort of the strangers who visited Edinburgh from any objects connected with art or with science, it derived from them an extraordinary degree of vivacity and interest."[294] Its name was the Oyster Club, and it may be thought from that circumstance that those great philosophers did not spurn the delights of more ordinary mortals. But probably no three men could be found who cared less for the pleasures of the table. Hutton was an abstainer; Black a vegetarian, his usual fare being "some bread, a few prunes, and a measured quantity of milk diluted with water"; and as for Smith, his only weakness seems to have been for lump sugar, according to an anecdote preserved by Scott, which, trivial though it be, may be repeated here, under the shelter of the great novelist's example and of Smith's own biographical principle that nothing about a great man is too minute not to be worth knowing.