Which be they?
I. Synthesis, whereby the divided Parts are re-united; as in Wounds. II. Diæresis, that divides and separates those Parts, which, by their Union, hinder the Cure of Diseases, such is the continuity of Abscesses or Impostumes which must be open'd to let out the purulent Matter. III. Exæresis, which draws out of the Body whatsoever is noxious or hurtful, as Bullets, Arrows, &c. IV. Prosthesis adds some Instrument or Body to supply
the defect of those that are wanting; such are Artificial Legs and Arms, when the Natural ones are lost. It also furnishes us with certain Instruments to help and strengthen weak Parts, such as Pessaries, which retain the Matrix in its proper place when it is fallen, Crutches to assist feeble Persons in going, &c.
What ought to be chiefly observed before the undertaking an Operation?
Four things; viz. 1. What the Operation to be perform'd is? 2. Why it is perform'd? 3. Whether it be necessary or possible? And 4. The manner of performing it.
How may we discern these?
The Operation to be perform'd may be known by its Definition; that is to say, by explaining what it is in it self: We may discover whether it ought to be done, by examining whether the Distemper cannot be cur'd otherwise: We may also judge whether it be possible or necessary, by a competent Knowledge of the Nature of the Disease, the Strength of the Patient, and the Part affected: Lastly, the manner of performing it may be found out, by being well vers'd in the Practice of Surgery.
What are the Fundamental Principles of Surgery?
They are Three in number: viz. 1. The knowledge of Man's Body. 2. That of the Diseases which require a Manual Operation. 3. That of proper Remedies and Helps upon every Occasion.
How may one attain to the Knowledge of Humane Bodies?