2l6 PHILOSOPHICAL TRANSACTIONS. [aNNO 1705. 



the trunks of the arteries of the leg, that were obstructed by petrifactions or 

 ossifications, in a person about the age of 67. Since which, I have met with 

 several of the hke instances in aged people, particularly in the legs of an old 

 gentleman ; whose toes and foot were sphacelated, in which the ossifications 

 diminishing their channels in some places, and totally obstructing them in 

 others, is made very evident. 



The dissections of morbid bodies not only instruct us in the seats and causes 

 of diseases, but very often inform us in the true use of parts, as will appear by 

 the following instances. The ossification or petrifaction in the great artery, at 

 its rise from the heart, has been so commonly found, that some think it is con- 

 stant ; how it may be in some animals I cannot be certain, but in human bodies 

 I am well assured that whenever it happens, it is a disease, and in some measure 

 incommodes those parts in the due execution of their office, as the following 

 cases will evince : but that this paper may be of some use, I shall set down the 

 symptoms before death, which may help our conjectures when the like offers 

 again. A thin man about 30, who languished with an ulcer in the thigh, at- 

 tended with a caries, or rottenness of that bone, at its articulation with the 

 tibia and patella, called the knee, where all those bones were affected, at length 

 fell into a true phthisis, and coughed up no small quantity of pus ; some months 

 before his death I frequently saw him, when he would often offer me his wrist, 

 to feel his unequal pulse, which was wont to amuse him ; the artery there miss- 

 ing sometimes one, sometimes too strokes in six or seven ; at first he told me 

 he observed it missed but one in ten, but at length those stops became more 

 frequent, especially on any agitation of the body or mind, though a polypus in 

 any of the great vessels about the heart may induce that symptom, yet its con- 

 tinuance so long before death, shows it owing to some other cause, as appeared, 

 on opening the heart and great artery of this person* 



PI. 8, fig. 11, represents the trunk of the great artery opened and displayed, 

 aaa the three semilunar valves of the aorta, which hinder the blood from return- 

 ing to the heart after it is expelled thence by its systole or contraction; these 

 valves in this case were somewhat thicker, and not so pliable as naturally, and 

 did not so adequately apply to each other; as is expressed by aaa, fig. 14, 

 Whence it happened sometimes that the blood in the great artery (aaa fig. 1 1 ) 

 would recoil, and interrupt the heart in its systole. But this stubbornness of 

 these valves was owing to a bony or stony substance, marked in the said figure, 

 which appeared much plainer when the valves were dry, as represented in the 

 figure beneath, marked with an * ; aa the two valves pinned out and dried ; b 

 the petrifaction or stony body at their junction. In this instance I observed the 

 left ventricle of the heart, expressed at gg, dd, ee, ff, to be a little dilated 



