They exemplify in every line his clearness of thought, and his care in deducing no other conclusion from the premises than that which they logically justify. The observations which he has annexed to his paper also are just, and of great practical value; they discuss the bearing that the whole has to the relation which exists between the skin and lungs, and the influence of this on the causes of that fell destroyer, popularly known under the title of Consumption. They are a portion of that investigation of relation between various organs, on which anything like the formation of a definite and practical science must ultimately depend. We shall endeavour, in the sequel, to explain the ulterior consequences which necessarily arise out of such considerations, when they are duly followed out. We shall endeavour to point out the share they had, in conjunction with other considerations, in leading to those beautiful and simple principles which Mr. Abernethy was led more especially to advocate; and show how far _he_ went, as describing the starting point of those who have endeavoured at a fuller development of the consequences of his views. He remarks, justly enough, on the determination to the lungs consequent on the repression of the surface, and the necessary _additional duty thrown on those_ important organs engaged in a common function with the skin, where the duty of the latter is not performed; and on the elements thus supplied for disease, _especially_ in persons of restricted chest; relations, _be it remembered_, which exist between the various other organs of the economy, and which exemplify in a single case truly, what has been, we trust, since shown in regard to organs generally; how the organ, which may be the seat of the _disease_, _may not be_ the seat of the original _cause_, but really a secondarily affected organ—a hint which, when followed out, is of _immense practical importance_. The skin is by no means the only organ which has a community of function with the lungs, or through which these important parts become affected; but if this be so, and diseases of the lungs be treated as an _integral thing_, it requires no great penetration to see how diseases so handled must be incurable; since the real cause may never be ministered to. Again, if a case should be successfully treated, by means which afford all possible relief to the _lungs_, whilst the _primarily affected_ organ is also properly treated, it by no means follows that the treatment should be the same in _every case_; for the primarily affected organ may be different in different cases. There is, in fact, no organ of the body which, when subjected to disordering influences, may not _secondarily_ affect the lungs.