be ambitious of noting all his cases, according to nosological arrangement, precision, in this respect, must be continually purchased at the expense of truth. I, at least, have long, and with oft renewed efforts, endeavoured to attain this enviable accuracy, but have never yet succeeded. The cause of this discordance between nosological character and actual disease, is easily discovered. The character is not drawn from any individual instance, but is derived from numbers, and, in this way, a perfect disease is supposed to be depicted. Of this each feature may, no doubt, be true to nature, yet the assemblages are very rarely found so combined; whence nosological character proves rather an ideal exemplar, than a true prototype.
But, waving this source of imperfection, the mode of judging diseases by nosological character, is fraught with further evils of an influence injurious to medical science. The character itself, however perfectly drawn from accurate observation of numerous specimens, must, of necessity, be incomplete. It may pourtray, with sufficient accuracy, the assemblage of symptoms co-existent at a particular stage of disease; but this stage is not the commencement, and to refer to it as if it were, can be productive only of confusion and error. Antecedently to this stage there is always an interval of deranged function, marked by its appropriate phenomena, and capable of being ascertained by suitable examination. This antecedent stage is essential to a complete history of the disease, and an accurate knowledge of it is, perhaps, even more necessary than of any other, inasmuch as it best displays the morbid actions by which
