The role of the scientist changed dramatically. Greatest of all the new gentlemen scientists was Isaac Newton, whose experiments with the laws of nature were undertaken to reveal God, not to disprove his existence. Colonies were established along America's Atlantic coasts. The first, in Jamestown, Virginia, struggled to survive until the tobacco trade made it viable. Slaves were transported from Africa to service new colonies. The largest numbers were taken to Brazil by the Portuguese and Dutch, their short, brutal lives eked out on the sugar plantations. In Europe the economic center of gravity shifted north. The Dutch became rich on the South East Asian spice trade and Amsterdam began a golden age. Women entered business and great painters such as Rembrandt and Vermeer were commissioned by the emerging middle class. Europe began to eclipse Arabic and Chinese eminence in science. Visiting Jesuits proved to the Emperor in China that their knowledge of astronomy was more accurate than that of the Chinese.