There is, however, a third point, of great practical consequence, on which Mr. Abernethy has been misunderstood. I allude to the local condition under which the puncture should be made. When, notwithstanding our persevering observance of all measures calculated to repress the diseased actions, or to procure the absorption of the deposited fluid, we perceive it to be increasing or approaching the surface, _then, before any inflammation_ of the skin has taken place, it should be discharged. In many cases, _this_ opening has been delayed until the skin _has become inflamed_, or much attenuated. Now this risks the accomplishment of an object which it is a material point with Mr. Abernethy to secure—namely, the _immediate healing_ of the puncture. On this point, even so good an authority as Sir Astley Cooper has given a misdirection. "Let the abscess proceed," says Sir Astley, "until you observe a blush or redness on the skin, and then adopt Mr. Abernethy's plan." Now this direction does not absolutely prohibit the opening of the cyst with the object which Mr. Abernethy had in view; but, as before stated, it deprives us of _one most desirable condition_. To settle this point, we quote Mr. Abernethy's own words. In discussing the point of time at which the opening should be made, he asks: "Are we to wait until evident _signs of inflammation_ appear? I think not." Accordingly, in a case where the surface had become red, we find he took care to _avoid_ opening it _at that part_; because it risked the security of at once healing the puncture. The truth is, that the _whole_ of the plan is most valuable; but it must be carefully followed _in its integrity_; and that this may be done, the principles on which it is founded must be constantly kept in mind. These are—the improvement of the general health, with the view of arresting the action of disease, and producing the absorption of the morbid secretion. This failing, to puncture the abscess, so as to secure the discharge of its contents without the admission of air, and on conditions calculated to _ensure_ the immediate healing of the wound; then to favour the approximation of the sides of the cavity, by relieving it of its contents, by puncturing it anew, _before_ it shall have become so much distended. Another misapprehension has arisen with regard to Mr. Abernethy's object in excluding air; and unnecessary pains have been taken to show that the presence of air is not injurious to living surfaces. It was not from any apprehension of this kind that he was anxious to exclude the air; but from the tendency that the _presence of air_ had to favour the _putrefactive decomposition_ of the new secretion. We must not omit to mention the origin of this instructive paper, as it is highly characteristic of Abernethy's acuteness of observation, and his promptitude in the practical application of it.