moira, 
so thanks to the lunacy of american traditional i can provide this horrible data:
1/12 tsp ≈ 1 pinch plus one drop
which is to say 1/16th + 1/64th teaspoons
(round 'em a little to make up the shortfall)
which is to say can we please be metric now please i'm begging you save me from this bullshit xD
