268 Hillebra/nd and Sehaller — Mercury 



]S^Hg - 2 X.,rH 2 0, in which X represents CI and SO,. It is even 

 insufficient for the chlorine alone in snch a formula and we are 

 therefore obliged to consider the possibility of the body being 

 a mixture. Calomel as a constituent of such a mixture is ex- 

 cluded from consideration for the reason that but a trace is 

 indicated on dissolving the mineral in warm hydrochloric acid 

 and this appears to be derived from the gangne. Mercuric 

 chloride would seem to be excluded by its solubility in water. 

 As oxychlorides there would naturally be considered first ter- 

 linguaite and eglestonite, but both are excluded for the reason 

 that they yield calomel on solution in hydrochloric acid. It 

 remains to assume a mercuric oxychloride and then an oxysul- 

 phate, both of which might perhaps be formed simultaneously 

 with ]STHg 2 Cl.a?H„0 from a mercuric solution containing more 

 mercury than is needed by the ammonia present to form a com- 

 pound of this type. If, perchance, the oxychloride were 

 Hg 2 Cl„0, or HgO.HgCL, and allowance were made for it on this 

 basis in the ratio above given, the ratio of the residuals would 

 show an oxysulphate with Hg to S0 4 as 4 to 3*23 and compo- 

 sition nearly Hg 4 0(S0 4 ) 3 , or' Hg0.3HgS0 4 . The calculated 

 amounts of these salts would demand 0*33 per cent of basic 

 oxygen, an amount that happens to coincide almost exactly 

 with that indicated by the nitrogen determinations according 

 to the ammonium bromide method (p. 265), which as will be 

 remembered gave more than was obtained by other methods. 

 While the excess of ammonia obtained by the ammonium bro- 

 mide method is with considerable reason believed to be in part 

 due to the action of the aluminous gangue on the reagent, cal- 

 culation shows that it can not well have all originated thus. 

 If not, the only alternative, assuming that the tests were rea- 

 sonably correct, is that an oxy-salt of mercury must have given 

 rise to some at least of that excess of ammonia. The chief ob- 

 jection to accepting this alternative is the volume of oxygen cor- 

 responding to the required weight percentage, which if wholly 

 given off as oxygen gas on heating the mineral itself ought not 

 to have escaped detection and approximate measurement. 

 Still, it is conceivable that in this method of operating, the basic 

 oxygen might not all escape as gas. The evidence as to the 

 presence of a little basic oxygen is conflicting, and further spec- 

 ulation would be profitless in the present state of our knowledge 

 regarding this remarkable mineral. To assume that the nitro- 

 gen is very low and should be 2*885 per cent or exactly equiv- 

 alent to the chlorine, is opposed by much evidence, including 

 the fact that the sulphate would then be strongly acid. 



It is regrettable that the long labor has resulted in nothing 

 more definite than the fixing of this mineral as the first nat- 

 urally occurring member of the so-called mercury-ammonium 



