290 franklin: mercury ammonia compounds 



CHEMISTRY. — A theory of the mercury ammonia compounds. 

 Edward C. Franklin, Hygienic Laboratory, U. S. Public 

 Health and Marine Hospital Service. To appear in full 

 in the American Chemical Journal. 



The large number of products which have been prepared by 

 the action of ammonia on mercuric oxide and mercuric salts con- 

 stitute an obscure group of substances which has never received 

 adequate theoretical treatment. In the dictionaries and hand- 

 books of chemistry these products are for the most part described 

 as mercuriammonium compounds, that is to say, they are assumed 

 to be ammonium oxide, ammonium hydroxide or ammonium salts 

 in which ammonium hydrogen is to a greater or less extent sub- 

 stituted by mercury, or they are complex compounds containing 

 mercury substituted ammonium salts. 



According to the theory proposed by the writer the mercury 

 ammonia compounds, instead of being mercury substituted 

 ammonium salts and bases, are, as a matter of fact, either (1) 

 mercuric salts with ammonia of crystallization; (2) ammono- 

 basic salts; (3) mixed aquobasic ammonobasic salts or (4) mixed 

 aquo ammono bases. 



An attempt will be made here to give the results arrived at by 

 the author as applied to a few of the better known representatives 

 of the large class of mercury ammonia compounds leaving the 

 proofs of the inadequacy of the mercuriammonium theories 

 together with the detailed arguments in support of the writer's 

 theory of the nature of the mercury ammonia compounds to be 

 found in the longer paper. 



The fusible white precipitate. Over sixty years ago Kane gave 

 this compound the formula HgCl 2 .2NH 3 , expressed in terms of 

 modern nomenclature, and recognized it as a compound in which 

 ammonia plays a part analogous to that of water in salts 

 with water of crystallization. Since that time the compound 

 has been variously formulated as mercuridiammonium chloride, 



,NH 3 -C1 

 Hg\ that is, as ammonium chloride in which one hydrogen 



X NH 3 -C1 



of each of two molecules of ammonium chloride is replaced by 



