"Our laws, Lord Denman, lay down a principle that every man is presumed to be acquainted with the business, profession, or study to which he belongs, or to which he has devoted himself. The converse--a most rational converse, is that he is unacquainted with what he does not belong to, or has not studied; or, in plain terms, that he is unacquainted with that of which he knows nothing. Sir Isaac Newton would have been a most ignorant Juryman upon a case resting upon the details of business in the butter trade of Cork; and a Mr. Jones, in that trade, would be an equally ignorant Juryman on a case involving the complex observations and abstract calculations of Sir Isaac’s Observatory. Shakspeare, as a Juryman, would have been puzzled to determine a disputed point of commerce; and a tradesman would be as equally perplexed in deciding a point upon the machinery of Arkwright, or the steam-engine of Watts. In the present case, a man named Haslam, (but the name is immaterial, for I apply myself to abstractions and not to individuals,) has devoted himself to the study of a subject. He is evidently a man of strong mind, of great knowledge, and of the most honest intentions. On many points I differ with him, but individual or public difference is not the case at issue. His very able work is submitted, not to the public mind, but to ’Trial by Jury;’ and its merits or demerits are determined upon by merchants, brokers, tradesmen. "Our laws, Lord Denman, lay down a principle that every man is presumed to be acquainted with the business, profession, or study to which he belongs, or to which he has devoted himself. The converse-a most rational converse, is that he is unacquainted with what he does not belong to, or has not studied; or, in plain terms, that he is unacquainted with that of which he knows nothing. Sir Isaac Newton would have been a most ignorant Juryman upon a ease resting upon the details of business in the butter trade of Cork; and a Mr. Jones, in that trade, would be an equally ignorant Juryman on a case involving the complex observations and abstract calculations of Sir Isaac’s Observatory. Shakspeare, as a Juryman, would have been puzzled to determine a disputed point of commerce; and a tradesman would be as equally perplexed in deciding a point upon the machinery of Arkwright, or the steam-engine of Watts. In the present case, a man named Haslam, (but the name is immaterial, for I apply myself to abstractions and not to individuals,) has devoted himself to the study of a subject. He is evidently a man of strong mind, of great knowledge, and of the most honest intentions. On many points I differ with him, but individual or public difference is not the case at issue. His very able work is submitted, not to the public mind, but to ’Trial by Jury;’ and its merits or demerits are determined upon by merchants, brokers, tradesmen and jobbing peculating Jurymen called ’Tales.’ as totally ignorant of