Salt of Tobacco • vjj 
Brad, which has its Head or larger End flat* 
Both thefe are fhewn at a, Plate VIII. 
When a little more Heat has been given* 
other Spiculce are produced from the Edge, 
whole Ends fpread on either Side, and then 
terminate in a Point: and which have all 
along their Sides triangular pointed Cryflals, 
not oppofite to one another, but placed al¬ 
ternately, fo as to reprefent a Zigzag with a 
Line drawn through its Middle, vid. L—-The 
regular Cryflals of this Salt are produced in 
the Middle of the Drop, being either Hex¬ 
agons or Rhombi, as ^t c . 
When the Moifture is nearly exhaled, 
there are fometimes feen to Ihoot from, or 
rather under the Spiculce, upon the Plane of 
the Glafs, a Reprefentation of Leaves, very 
fmall at their firE Appearance, but increafing 
gradually to what is fhewn at d .—-Thefe I 
have feen but twice. 
A violent Agitation may be difcovered in 
the Fluid by the firE Magnifier, during the 
whole Procefs, but chiefly at the Beginning, 
and extremely minute Cryflals rifing from 
the Bottom. 
Oil of Tobacco is a flrong Poifon to many 
Animals: ’tis faid a Thread wetted there¬ 
with, and drawn by a Needle through the 
Skin on the Back either of an Eel or Viper, 
will make it die immediately. This I have 
never tried. 
Vol.IL n chap. 
I 
