( 117 ) 



behind the otlier, owing to the piece of tooth being thicker in that 

 part, for this fmall fragment was fpht off, and not cut from the 

 tooth. 



The breadth of this tooth was ahnofi: two fifth parts of an incii, 

 and from the befl: computation I could make, I judged that within 

 the forty-fifth part of an inch, I faw an hundred and twenty of 

 the tubuh, which amounts, in the fpace of one inch in length, to 

 five thoufand four hundred : now fuppofing this molar tooth, or 

 grinder, before defcribed, to be of a round figure, the diameter of 

 it would be 2150 times the thicknefs of one of the tubili of which 

 the fame is compofed, and when this number is multiplied into itfelf, 

 the produ6l is 4,822,500. In a word, the proportion of one of 

 the boney tubili to the fize of fuch a tooth, is as one to 4,822,500 



Notwithftanding I had now obtained a very fatisfadlory infight 

 into the formation of the human tooth, I was not yet content, but 

 became defirous to examine into the nature of the fubftance, or 

 veflels contained in the cavity, and for this purpofe, I procured 

 I'ome of the fore teeth, and the jaw-bone of an ox, which were 

 taken out and brought to me immediately after the animal had been 

 killed ; feveral of thefe fore-teeth, and fome of the grinders, I broke, 

 or fplit open, and with great admiration obferved, that thofe veflels, 

 which, palling through fmall apertures in the lower part of the 

 tooth, filled ail the cavity within, confifted of fuch an inconceiv- 

 able number of blood- veflels, and other veflels, as to furpafs all 

 imagination: indeed, many of them. I obferved to be as fmall and 

 flender as the tubili themfelves, of which the tooth was formed ; 

 and among them were fmall blood-veflels branching out into fiill 

 fmaller ones, many of them entirely colourlefs; therefore, I thought 

 it probable that there might be ftill fmaller veflels entirely undif- 

 cernible by our fight. 



All thefe veflels were inclofed in a membrane, or coat, which 

 was eafily to be feparated from the bone, and, having kept fome 



