( 120 ) 



fize ; and if this is fo, what fhall we fay of the perfpirable parts of 

 our bodies ? I have ah-eady mentioned, that perfpiration may be 

 performed through the interlHces between the Scales, \\ hich mull 

 be in great numbers ; but the veflels compofing the Scales will 

 much exceed that number; for if thefe Scales are in contlant 

 growth, by the means of fuch veflels, then, by the continual mo- 

 tion of the body and of the thin juices, the perfpirable matter may be 

 expelled in great quantities through thefe veflels. 



And, to make a computation of the almotl infinite number of 

 thefe minute veflels, I placed fome of thefe Scales, taken from the 

 furface of the flcin, near fome grains of fand, and I judged that 

 the diameter of thefe grains was from ten to twenty times the dia- 

 meter of thofe Scales; and the Scales are, as before mentioned, 

 placed in a triple row one over another. I will take, there- 

 fore, the fmallell number, and fay, as I have before done, that 



23^ 250 Scales can be covered by a grain of fand. And 



500 fuppofing each Scale to be compofed of 500 vefl^els, 



J 25 000 then the perfpirable matter may be expelled through 



125,000 paflages, within the compafs of a grain of fand. 



befides the orifices or outlets it may find between the Scales. 



With a fharp-pointed infcrument I took from the arm of a Negro 

 girl, about thirteen years of age, a fmall portion of the upper Ikin, 

 and tound it to confift of nothing but Scales, joined together 

 as I have faid of my own Ikin ; but thefe Scales were no fo large, 

 by reafon, as I concluded, that the girl was not come to her full 

 growth ; for an infant has as many Scales on its body as a grown 

 perfon, and they increafe with it in fize. And I am certain, that 

 though a perch, jack, or cod-fifli, be no bigger than a joint "of 

 one's finger, their bodies will have as many Scales on them as when 

 they are grown larger. On placing thefe Scales, taken from the 

 Negro girl, before the microfcope, I found them not fo tranfparent 

 as thofe on my own body ; and in the place on her arm whence I 



