text: " The tanner who lives among his hides till he is insensible to their exhalations--the surgeon who has conquered the disgust with which the objects around him must fill an ordinary individual--the sensualist on whose jaded appetite all the resources of art and all the loveliness of nature are employed in vain--may serve as common instances of the first part of the proposition; and the astonishing facility acquired by particular men in the business with which they are conversant are proofs no less irrefragable of the second