( 3 ) 



one of thefe is Ihewn in fg. 7, where the perpendicular veflels 

 are exhibited lengthwife, and it may be- feen in the veflel marked 

 G G. The Imall perpendicular veflels are compofed of exceffively 

 thin membranes, and thefe it was not in my power to reprefent 

 truly in a drawing. 



In this wood I only obferved one fort of horizontal veflels, which 

 are lliewn lengthwife in Jig. 6, at E E E; the number of thefe is very 

 fmall, compared with the horizontal vellels I have obferved in other 

 woods. 



Fig. 7, H H, reprefents them cut tranfverfely, and intermixed 

 with the perpendicular veflels, which in the fame figure apj)ear 

 lengthwife. 



In one of the large perpendicular veflels reprefented in fig. 7, at 

 G G, I have fliewn the appearance they exhibit of being covered 

 with globules, but thofe .exceffively minute. 



Fig. 8, is a particle of Alder, about the thicknefs, when viewed 

 with the naked eye, of an hog's briflle : this wood has too forts of 

 perpendicular veflels; the fmaller ones confifl; of exceffively thin 

 membranes, the larger of membranes covered with particles of 

 wonderful minutenefs, and to which no other figure can be affigned 

 than that of globules. 



A B or C D denote the length of the tree's increafe in the Ipace 

 of one year; E E E E are the horizontal veflels. 



Fig. 9, F F F F, are the large pei-pendicular velTels cut longitu- 

 dinally ; H H are the fmall perpendicular veflels : G G, are the 

 horizontal veflels, which here are feen cut tranfverfely. 



Fig. 1 0, A B C D E F, is a fmall particle of Ebony, the growth 

 of the ifland Mauritius : this figure is drawn from a microscope, 

 magnifying objects much more than thofe from which the draw- 

 ings of the other woods were made, becaufe the veflels in this wood 

 could not be conveniently difcovered by a common magnifier. The 



