Of the Qiiills ufed in writ'mg, and their feathers : on human hair, and 

 the hair and xvool of anitnals. 



IVJ. Y reflexions on the nature of thofe Quills with which we w'rite. 

 as alfo on the general make of the feathers of birds, led me to an 

 inquiry into the manner of their formation ; which at length I dif- 

 covered, and found, that Quills are compofed of frreaks, or more 

 properly fpeaking, veflels. Thefe vefl'els, in every Ouill, are three- 

 fold. The firfi:, or external ones, w-hich conftitute but a fmall part 

 of the Quill, are parallel to its length: the fecond, which are 

 in a much larger quantity, take their courfe round about the 

 Ouill, wiuhin the former ones : thel'e fecond fort of veflels are not 

 fo clofely united as to form what may be likened to a folid body, but 

 lie one on another like fcales or coats, in fuch manner, that the dif- 

 ferent la}'ers of them may be plainly perceived : the thii'd fort of 

 veflels, which compofe the thickefl or greateft part of the Ouill, lie 

 lengthwife, in hke manner as the firfl; mentioned ones : this third 

 fort of veflels, are alio difpofed in the manner of fcaly parts laid one 

 on another ; and, confldering the thinnefs of a Quill, and the large 

 cavity it contains, its formation is, in my judgment, the ]nofl perfe6t 

 that could be contrived ; for, hereby it is made tough and ftrong, 

 both in its circumference, and in its length. To exhibit the nature of 

 it to the eye, I caufed a drawing to be made of one. 



In Plate IX. fg.i, ABCDEFG, reprefents a common gcofe 



LI 



