Studies in the Calcitc Group. 235 



work is also constant, then we should, given the specific gravity 

 of Ca]\Ig(C03)o, be able to calculate the specific gravities of 

 the various molecules that may replace it. On making these 

 calculations the following values are obtained, CaMg(C03)2 

 2.87, CaFe(C03), 3.36, CaMnCCOs), 3-34, MgCOa 2.62, CaCOs 

 3.1 1. These values were used to calculate the specific gravities 

 corresponding to the dififerent analyses. The measured and cal- 

 culated values together with their differences are given in the 

 columns I, II and III of Table V, the numbers corresponding 

 to the six doubtful analyses mentioned above having been 

 omitted from the list. 



Trans. Conn. Acad., Vol. XXII 17 1917 



