200 PHILOSOPHICAL TRANSACTIONS. [aNNO 1675. 



circumvolutions. — E. E. The volvulus itself, being a part of the intestinum ileum, 

 tied tightly by the ligature, and approaching to a state of sphacelation ; whence 

 a complete obstruction of the passage by stool was produced, so that the contents 

 of the small intestines were voided upwards by an almost incessant vomiting. — 

 F. Part of the intestinum ileum so constricted by the aforesaid preternatural 

 ligature, as to have the appearance of a blind gut. — G. The extremity of the 

 ileum where it becomes colon. — H. The colon a little contracted, but [in other 

 respects] of a natural appearance. — I. The caecum. 



OnAstroites or Star-stones. By Mr. Martin Lister. N° 112, p. 274. 



These astroites or star-stones, were brought me from the Yorkshire Wolds. 

 I have seen them dug out of a certain blue clay, on the banks of a small rivu- 

 let, at the foot of the Wolds. There are plenty of them washed into the brook; 

 but the most fair and solid are those that are got out of the clay. 



The matter and substance of these stones, if broken, is flint-like, of a dark 

 shining polish; but much softer, and easily corroded by an acid menstruum. 

 Vinegar indeed makes them creep ; but a stronger spirit, as of nitre, moves 

 them violently. I doubt not but they will readily calcine, as the belemnites, to 

 a very strong and white lime. These stones are all fragments, as we have 

 observed of the entrochi; either one single joint, or two, three, or more joints 

 set together, forming a five- sided column. I have not yet had any piece much 

 above 1 inch long, which consisted of 18 joints; but I have seen one piece, 

 somewhat shorter than the former, which had 15 joints. Every joint consists 

 of 5 angles, which are either jutting out and sharp, and consequently the sides 

 of pieces, made up of such joints, are deep channelled; or the angles are blunt 

 and round, and the sides plain or very little hollowed. Where the joints are 

 thin or deep, they are so equally throughout the whole piece ; yet there are 

 some, though very few pieces, which consist of joints of unequal thickness. 

 Many of the thick-jointed pieces have certain joints somewhat broader, or a 

 very little standing out at the angles, and thereby the joints are distinguished 

 into conjunctions of two, three, or more joints: and these conjunctions are very 

 observable in the thin-jointed stones, and are marked out with a set of wires. 



The thickest piece yet come to my hands, is not above an inch and a half 

 about, and those very rare too: from which size to that of a small pin, I have 

 all the intermediate proportions; and these so exceedingly small pieces are as 

 exactly shaped as the largest. Most pieces, if not all, of any considerable length, 

 are not straight, but visibly bent and inclining. All the pieces of any sort are 

 much of an equal thickness, or but little tapering ; yet one of the ends, by 

 reason of a top joint, is visibly the thickest. This top joint has five blunt 

 angles, and is not etched or engraven, or but very faintly, on the outside. 



