ISl NOMENCLATURE 



thumb. From digitus and palmus, we form digitalis and 

 palmaris : this last, however, must be carefully distinguished 

 from palmatus, which means, divided like the hand. The 

 measure of which we are now speaking, is about three 

 inches. 



The small span (spithama, whence spithameus) is the dis- 

 tance between the thumb and middle-finger, when they form 

 a span. This measure, in full grown men, is about seven 

 inches. 



The great span {dodrans, whence dodrantalis) is the dis- 

 tance between the thumb and little finger, when they form a 

 span. It amounts to about nine inches. 



The foot (pes, whence pedalis) is the length of the sole of 

 the foot, when it is of a large size, or the distance of the 

 elbow-joint from the wrist. It is usually taken for a geome- 

 trical foot. But pedalis must not be confounded with peda^ 

 ttis, which denotes the foot-shaped position of the leaves. 



We next take the distance from the elbow-joint to the 

 point of the middle finger. This is called cubitus, whence 

 €ubitaUs ; its length is about a foot and a half 



Next comes the length of the arm, (brachium, whence bra^ 

 'chialis : as also ulna, ulnaris). This is reckoned about two 

 feet. 



Lastly, there is the fathom, {orgy a, orgyalis), or the dis- 

 tance of the points of the fingers, when the arms of a man 

 are extended. This measure is taken from the length of a 

 man of large size : it is hence reckoned about six feet. 



Whatever exceeds this measure, is reckoned in so many 

 iathoms or feet% 



17. 



tt is an unaccommodating practice which has been adopted 

 Iby the French Natural Historians, of constantly employing the 

 decimal measure, which is entirely unknown out of France^, and 

 which is particularly unsuitable to this purpose, on account 

 of the very great exactness with which its subdivisions are 

 given. We only state here, therefore, that the metre amounts 

 to three feet and something more than eleven lines ; that the 



