'When I returned to Annan, it occurred to me, that it would be proper to see what was become of my Hall discourses. It occurred to me, much about the same time, that it would be proper to study Rumfords essays, Mackenzies travels, Humboldts New Spain, Berkeley's principles of knowledge, Stewarts essays, Simson's fluxions &c &c &c - It was some great man's advice, to every person in a hurry - never to do more than one thing at a time. Judge what progress I must have made - when I engaged in half-a-dozen. - Manufacturing theses - wrestling with lexicons, Chemical experiments, Scotch philosophy and Berkeleian Metaphysics - I have scarcely sufficient strength left, to write you even now. Upon consideration, therefore, of these egregious labours - I hope, you cannot refuse to forgive me.'