In our brief sketches of Abernethy's works, we are quite as desirous of showing why he did not do more, as we are of setting down faithfully our many undoubted obligations to him. This, indeed, is the best mode of giving an onward impulse to those approaches towards a definite science which (John Hunter excepted) he was the first to secure. If we would increase the usefulness of those beautiful principles which he has left us, we can hardly do better than endeavour to point out any error or deficiency in the investigation of any subjects to which such principles may be applicable. His work on "Tumours" contains much that is interesting in regard to the peculiar character of his mind, and his aptitude for simplification. He does not undertake a thorough investigation of the subject. His object seems to have been to place in an intelligible order, to chronicle and mark, that which was _really_ known; to pack together, as it were, that which was clear and positive, in a form convenient for consideration; to remove that disorder and obscurity which seem to hang about the threshold of all inquiries, and substitute so much of arrangement and perspicuity as might invite, and perhaps facilitate, further investigation. He states the more important circumstances which he had observed, and conducts his classification of the so-called "Tumours" on a basis as scientific as it could be on an imperfect induction of facts. He did this in a way eminently characteristic of his quick perception, in seizing those properties on which a nomenclature should be based, and in marking those distinctions which, in a practical science, must always be regarded as of the greatest value. He founded his nomenclature chiefly on certain resemblances, observed in these diseases, to well-known structures of the body. The simplicity of this plan, so long as the resemblance is obvious, is just that which constitutes excellence in nomenclature. To take an example, amongst others, he says there is a tumour the structure of which resembles the Pancreas, or Sweetbread as it is popularly called, and to this tumour he gives the name of Pancreatic. Now every one knows a sweetbread, and the name implies no opinion whatever as to its nature; it simply declares a fact. Whatever we may ultimately discover with regard to tumours, a name of this kind, though it may possibly be exchanged for one more significant of the nature of the disease, will still leave us nothing to unlearn; for the tumour in question will always have that resemblance from which Mr. Abernethy named it; and if we should find (as indeed we do find), in course of time, that diseases undergo alterations of type, the rarity of a tumour resembling the sweetbread would record that circumstance.