Arbor Veneris, or, the Copper Tree. 2 og 
On the contrary, if too much Tin be diiTolv- 
ed in the AquaFortis it becomes whitilh or 
milky, diffolves not enough of the Copper* 
and is too weak for Vegetation. Difap- 
pointments will alfo happen if Care be not 
taken in proportioning'the Mercury and Salt 
Ammoniac , when they are employed: and 
yet the certain Weight and Meafure cannot 
be laid down, from the great Difference in 
Aqua Fort is. 
The Nail or Piece of Iron fhould be filed 
bright at the Time ’tis uied, and its Surface 
made fo even that it may come clofe to the 
Glafs its whole Length. "Tis beff to hold 
the Nail in the Mixture for a Second or two* 
till it is of a Copper Colour, before you 
place it upon the Glafs : your Shoots will 
thereby be made the flronger, as the Cop¬ 
per Particles floating in the fmall Quantity 
you put upon the Glafs, finding the Iron al¬ 
ready covered, will difpofe themfelves more 
into Branches. But doing this often w ill 
impoverifh your Mixture by drawing the 
Copper out of it: and therefore ’twill be right 
to keep fome feparately for fuch an Ufe. 
The Branchings pufh out to the Extremity 
of the Drop, and then frequently turn along 
the Edges, ftill dividing into fmaller Rami¬ 
fications, till at laft they run into one another 
and become confufed ; or elfe a yellow Tinge 
drawn from the Iron diffufes through the 
O 
Fluid and renders them obfcure; but neither 
5 . of 
