METALS AND METALLOIDS 705 



case with phenols and aromatic amines. The mercury enters 

 the amine molecule in two stages, the mercuri-acetate group 

 first attaches itself to the amino-nitrogen, and then swings into 

 the aromatic nucleus either into para- or the ortho-position in 

 accordance with the law governing substitution in the benzene 

 series. This process can be repeated, and in the case of ///^fa- 

 toluidine as many as three mercuri-acetate groups can be intro- 

 duced into the molecule : 



NH 2 



CH 3 . COOHgj-^-HgOOC . CH 3 



HgOOC . CH 3 



This compound contains 93 per cent, of mercury and is extremely 

 soluble in water. 



By heating mercuric acetate with aromatic compounds at 

 high temperatures, products are obtained containing mercury 

 attached to two organic radicals. 



Meta-nitrobenzoic acid and mercuric acetate yield such a 

 compound which on reduction furnishes an amino-acid, the 

 sodium salt of which has the following formula : 



Hg[C 6 H 3 (NH 2 ).C0 2 Na] 2 . 



2. The Masked or Hidden Condition of Metals and 

 Metalloids in their Organic Derivatives 



The above sodium salt of the mercury derivative of meta- 

 aminobenzoic acid is soluble in water, but owing to its double 

 attachment to carbon the mercury present in the salt does not 

 show its ordinary analytical reactions. Before the mercury can 

 be detected by the usual tests for the metal, its attachment to 

 the two aromatic rings must be destroyed. This masked con- 

 dition of the mercury extends to the physiological action of the 

 compound, which is thirty times less toxic than mercuric 

 chloride. The substance has marked bactericidal and spiro- 

 chaetocidal properties, and can be tolerated in large doses. A 

 rabbit weighing about 5 lb. was not injured by a one-gram dose 

 of this sodium salt. 



Mercury compounds with aromatic amines are likely to prove 

 of therapeutic value, as the amino groups have the property 

 of entering into combination with certain constituents of the 

 parasitic organisms binding drug and organism together, while the 

 poisonous metal does its work on the bacterium or spirochaete, 



