In the ensuing decade(s), sufficient progress has been made to at least suggest the importance of dry deposition, though precious few actual measurements exist. As might be expected, most all of the methodology developed during the acid rain era for S & N has been applied to Hg in some fashion. On one hand, dry deposition has been estimated from leaf-washing xperiments (with little assurance that dry deposited Hg can be effectively washed from leaves), from various gas exchange chambers (does only gaseous Hg matter?), from the ecosystem fluxes throughfall and litterfall (what about complications from soil uptake and foliar leaching?), and data exist for deposition to surrogate surfaces (of exactly what one wonders?). On the other hand, a few estimates have been derived from micrometeorological measurements (including concentration gradients, modified Bowen ratio, and relaxed eddy accumulation). Of course (and I say this fondly), there are any number of model estimates (“caution, you are entering a data-free zone”). In these musings I’ll attempt to explore what we do, what we don’t, and what we only think we know about Hg dry deposition, and why that matters.