120 PHILOSOPHICAL TRANSACTIONS. [aNNO 1666. 



Stone and gravel in human bodies, or to ^ssolve those concretions after they 

 have been there formed.* 



To such reflections an extraordinary case is added by Dr.Beale, being a narrative 

 of a stone not long since taken out of the womb [or bladder ?] of a woman in 

 his neighbourhood, near Trent in Somersetshire, by incision, and who after- 

 wards was perfectly cured, though she had carried the stone with extreme tor- 

 ments for eight or nine years. The operation was performed at Easter 1666 ; 

 after which time he weighed the stone and found it wanted somewhat of four 

 ounces, though it had lost of the weight it formerly had, being very light for a 

 stone of that bulk. He further describes it to be of a whitish colour, lighter 

 than ash-colour. It had no deep asperities, and had somewhat of an oval figure, 

 but less at one end than a hen's egg, and larger and blunter at the other than 

 a goose's egg. 



Of IVorms that eat Stones and Mortar. By M. de la Voye. 



N' 18, p. 321. 



In a large and very ancient wall of free-stone in the Benedictins Abbey at 

 Caen in Normandy, facing southward, are found many stones so eaten by 

 worms, that one may run one's hand into most of the cavities. In these cavities 

 there is abundance of live worms with their excrement, and of the stone dust 

 which they eat. Between many of the cavities there remain but leaves as it 

 were of stone, very thin, which part them. I have taken some of these living 

 worms, which I found in the eaten stone, and put them into a box with several 

 bits of the stone, leaving them there together for the space of eight days ; and 

 then opening the box, the stone seemed to me so sensibly eaten, that I could no 

 longer doubt of it. 



These worms are inclosed in a shell which is grayish, and of the size of a 

 barley-corn, sharper at one end than the other. By means of an excellent mi- 

 croscope I have observed, that this shell is all overspread with little stones and 

 small greenish eggs ; and that there is at the sharpest end a little hole, by which 

 these creatures discharge their excrement; and at the other end a somewhat 

 larger hole, through which they put out their heads and fasten themselves to 

 the stones they gnaw. They are not so shut up but that sometimes they come 

 out and walk abroad. They are all black, about two lines of an inch long, and 

 three quarters of a line broad. Their body is distinguished into several plies or 



* The mode in which petrifactions are formed is now very well understood ; but the knowledge 

 of this natural process throws no light either upon the origin of urinary calculi (whose chemical com- 

 position is different) or upon the means of preventing their formation. 



