Vitus - thanks for that tidbit - I did not know that....
Os' post:
Post 233238 (https://www.thevespiary.org/talk/index.php?topic=6865.msg23323800#msg23323800)
(Osmium: "Re: Debunking the Hg2Cl2 myth", Chemistry Discourse)
Post 464012 (https://www.thevespiary.org/talk/index.php?topic=6071.msg46401200#msg46401200)
(abuse: "Mecuric Iodide for Methyl Mans Al/Hg", Chemicals & Equipment)
HgI2 seems to be what bees recommend anymore (right?) because of the toxicity of HgCl2.
The toxicity of mercury salts varies with their solubility. Usually mercury (I) compounds are of low solubility and significantly less toxic than mercury (II) compounds.
Inorganic mercury salts present a far greater hazard than elemental mercury if ingested orally, owing to their greater water solubility. For mercury (II) chloride, the lethal dose may be as small as 0.5 g, compared with 100 g mercury metal.
Mercury salts are usually non-volatile solids, so poisoning by inhalation is rare, though toxicity may arise if aerosols are deposited in thelungs. Once adsorbed, the mercury (I) form will readily react with the thiol groups of amino acids such as cysteine. The protein metallothionein, functions as a natural chelator, preventing damage by mercury and other transitional metals to thiol-containing proteins. Once metallothionein proteins are saturated, other structurally related proteins can be damaged. Inorganic mercury salts are not lipid soluble, and so do not cross the blood brain barrier in significant amounts. The majority of the dose of an ingested inorganic mercury salt accumulates either in the liver, where it is excreted in the bile or in the kidney, where it is excreted in the urine
http://www.hyp.ac.uk/bhs/toxicity%20of%20mercury.pdf (http://www.hyp.ac.uk/bhs/toxicity%20of%20mercury.pdf)