418 Progress of Foreign Science. 
carbonate of lime, dolomite, and brownspar ; or the same as the 
relation between the arseniate and phosphate of ammonia. 
Mr. M. proposes to demonstrate more completely in an ap- 
proaching memoir, the law for the relation between the chemical 
composition and crystalline form, which may be thus stated: 
The same number of atoms combined in the same manner produces 
the same crystalline form; and the same crystalline form is inde- 
pendent of the chemical nature of the atoms, being determined 
only by their number and relative position. 
Bin-arseniate or Bi-phosphate of Potash. 
Arseniate or Phosphate of Soda. 
Fig. 5. ° 
