Sec. 413. When the obstructing Bodies are small, and only stop up Part of the Passage; and which may either easily elude the Hook, or straiten it by their Resistance, a Kind of Rings may be used, and made either solid or flexible. The solid ones are made of iron Wire, or of a String of very fine brass Wire. For this Purpose the Wire is bent into a Circle about the middle Part of its Length, the Sides of which Circle do not touch each other, but leave a Ring, or hollow Cavity, of about an Inch Diameter. Then the long unbent Sides of the Wire are brought near each other; the circular Part or Ring is introduced into the Gullet, in order to be conducted about the obstructing Body, and so to extract it. Very flexible Rings may be made of Wool, Thread, Silk, or small Packthread, which may be waxed, for their greater Strength and Consistence. Then they are to be tied fast to a Handle of Iron-Wire, of Whale-bone, or of any flexible Wood; after which the Ring is to be introduced to surround the obstructing Substance, and to draw it out. Several of these Rings passed through one another are often made use of, the more certainly to lay hold of the obstructing Body, which may be involved by one, if another should miss it. This Sort of Rings has one Advantage, which is, that when the Substance to be extracted is once laid hold of, it may then, by turning the Handle, be retained so strongly in the Ring thus twisted, as to be moved every Way; which must be a considerable Advantage in many such Cases. Sec. 414. A fourth Material employed on these unhappy Occasions is the Sponge. Its Property of swelling considerably, on being wet, is the Foundation of its Usefulness here. If any Substance is stopt in the Gullet, but without filling up the whole Passage, a Bit of Sponge is introduced, into that Part that is unstopt, and beyond the Substance. The Sponge soon dilates, and grows larger in this moist Situation, and indeed the Enlargement of it may be forwarded, by making the Patient swallow a few Drops of Water; and then drawing back the Sponge by the Handle it is fastened to, as it is now too large to return through the small Cavity, by which it was conveyed in, it draws out the obstructing Body with it, and thus unplugs, as it were, and opens the Gullet. As dry Sponge may shrink or be contracted, this Circumstance has proved the Means of squeezing a pretty large Piece of it into a very small Space. It becomes greatly compressed by winding a String or Tape very closely about it, which Tape may be easily unwound and withdrawn, after the Sponge has been introduced. It may also be inclosed in a Piece of Whalebone, split into four Sticks at one End, and which, being endued with a considerable Spring, contracts upon the Sponge. The Whalebone is so smoothed and accommodated, as not to wound; and the Sponge is also to be safely tied to a strong Thread; that after having disengaged the Whalebone from it, the Surgeon may also draw out the Sponge at Pleasure.