It will be impossible for us to consider the Laws of Nature, and what they effect, unless we now and then give our sole attention, so as to obtain a clear idea upon the subject. Give me now that attention, and then I trust we shall not part without your knowing something about those Laws, and the manner in which they act.
In: William Crookes, A Course of Six Lectures on the Various Forces of Matter and Their, Relations to Each Other, Lecture II (p. 31)