Among the innumerable mortifications that waylay human arrogance on every side may well be reckoned our ignorance of the most common objects and effects, a defect of which we become more sensible by every attempt to supply it. Vulgar and inactive minds confound familiarity with knowledge, and conceive themselves informed of the whole nature of things when they are shewn their form or told their use; but the speculatist, who is not content with superficial views, harrasses himself with fruitless curiosity, and still as he enquires more perceives only that he knows less.