However, practical anatomy, such as it is, is concerned with an exact knowledge of the relationship of organs as they stand in reference to each other, and to the whole design of which these organs are the integral parts. The figure, the capacity, and the contents of the thoracic and abdominal cavities, become a study of not more urgent concernment to the physician, than are the regions named cervical, axillary, inguinal, &c., to the surgeon. He who would combine both modes of a relationary practice, such as that of medicine and surgery, should be well acquainted with the form and structures characteristic of all regions of the human body; and it may be doubted whether he who pursues either mode of practice, wholly exclusive of the other, can do so with honest purpose and large range of understanding, if he be not equally well acquainted with the subject matter of both. It is, in fact, more triflingly fashionable than soundly reasonable, to seek to define the line of demarcation between the special callings of medicine and surgery, for it will ever be as vain an endeavour to separate the one from the other without extinguishing the vitality of both, as it would be to sunder the trunk from the head, and give to each a separate living existence. The necessary division of labour is the only reason that can be advanced in excuse of specialisms; but it will be readily agreed to, that that practitioner who has first laid within himself the foundation of a general knowledge of matters relationary to his subject, will always be found to pursue the speciality according to the light of reason and science. Anatomy--the [Greek words], the knowledge based on principle--is the foundation of the curative art, cultivated as a science in all its branchings; and comparison is the nurse of reason, which we are fain to make our guide in bringing the practical to bear productively. The human body, in a state of health, is the standard whereunto we compare the same body in a state of disease. The knowledge of the latter can only exist by the knowledge of the former, and by the comparison of both. Comparison may be fairly termed the pioneer to all certain knowledge. It is a potent instrument--the only one, in the hands of the pathologist, as well as in those of the philosophic generalizer of anatomical facts, gathered through the extended survey of an animal kingdom. We best recognise the condition of a dislocated joint after we have become well acquainted with the contour of its normal state; all abnormal conditions are best understood by a knowledge of what we know to be normal character. Every anatomist is a comparer, in a greater or lesser degree; and he is the greatest anatomist who compares the most generally.