THE Patient being laid on a horizontal Table, with his Thighs elevated and a little extended, pass the Sound with the concave Part towards you, 'till it meets with some resistance in Perinæo, a little above the Anus; then turning it without much Force, push it gently on into the Bladder; and if it meets with an Obstruction at the Neck, raise its Extremity upwards, by inclining the Handle of it towards you; or if it don't then slip in, withdraw it a quarter of an inch, and introducing your Forefinger into the Rectum, lift it up, and it will seldom fail to enter: There is some Art in turning the Sound in the proper Place of the Urethra, which Surgeons not versed in this Operation cannot so well execute; therefore they may pass the Instrument with the concave Side always towards the Abdomen of the Patient, observing the same Rule at the Entrance into the Bladder, as in the other Method. The Cause of this Obstacle, besides the Rugæ of the Urethra, and the Resistance of the Verumontanum, is sometimes a small Projection of the Orifice of the Bladder, in the Urethra, like that of the Os Tincæ in the Vagina, which occasions the End of the Sound to slip a little beyond it.

It is not to be supposed, that by searching, one can possibly judge of the Size and Form of a Stone; and indeed the Frequency of the Fits, and Violence of the Symptoms, are a better Rule to go by; though who ever shall think himself capable of distinguishing absolutely the Difference of Stones, even by these Circumstances, will sometimes be mistaken; since the Frequency and Violence of the Pain depend not always merely upon their Magnitude or Shape; and there are some Instances, where a Stone of six Grains weight, has for several Months given more Pain in one Person, than a much larger has in another, however, cæteris paribus, a large or a rough Stone is worse than a small or a smooth one.

Though upon searching, we are assured of a Stone in the Bladder, we are not without further Inquiry, to operate immediately; since there are sometimes Obstacles which forbid the Operation, either absolutely, or only for a certain time; among these, that of greatest Consequence, is the Gravel or Stone in the Kidneys, which is known by the Pain in the Loins, Vomitings, Contractions of the Testicles, Numbness of the Thighs, and often by Matter which the Inflammation produces in the Kidneys. The Objections of less Weight, and which frequently are removed; are a Fit of the Stone, a Cough, a Hectic, and being emaciated by long Pain; excessive hot or cold Weather, are likewise Hindrances: But in extremity of Danger, these last Considerations may be disregarded, tho' no doubt very hot Weather is more inconvenient and dangerous than cold, as lying abed is then more troublesome, and the Urine much saltier.

Difference of Age makes an extreme Difference in Danger, Infants and young People almost always recovering; but still the Operation is advisable on those advanced in Years, tho' it, is not attended with near the same Success. This Operation is performed four several Ways, all which I shall describe with their particular Inconveniencies, that we may the more easily pitch upon that which has the least.

Before we perform any of them, 'twill be proper to prepare the Patient with a gentle Purge, the preceding Day, and a Clyster early in the Morning, which will be of great service in cooling the Body, and making some of the Operations less dangerous where the Rectum is liable to be wounded, when full.