f 569 ] 
tempi a ting fome Part thereof, and perhaps is not 
exhibited in the fame View by others, it may not 
be improper to annex it in this Place : Which is to 
demonftrate this common logarithmic Property, that 
the Fluxion of a Number divided by that Number , 
is equal to the Fluxion Napierian Logarithm 
of that Number. 
Let BEG be a loga- 
rithmic Spiral, cutting its 
Rays at Angles of 4,5* De- 
grees: Then, if A E be 
taken as a Number, BC 
will be its Napierian or 
hyperbolic Logarithm. 
Alfo, let C' Z) exprefs 
the Fluxion of the Loga- 
rithm BCi and the cor- 
re'ponding Fluxion of the 
Number AE, will be re- 
presented by FG , or its 
Equal FE-, as the Angles 
FEG and FGE are equal. 
Now, AC :CT):: AE: ( EF= ) FG. 
Therefore CT> = * AB. , 
And if AB be taken as the Unit or Term from 
whence the Numbers begin : 
Then CT> = /. d. 
va, 
