APPENDIX. 245 



b. The residue was taken up by water, and mixed with acetate of 

 .ime ; the residue being dried and heated to redness, was treated with 

 acetic acid (c), and the portio.i not dissolved was estimated as pure 

 phosphate of lime, of which it was assumed that 100 parts corresponded 

 to 129 parts phosphate of potash ; for 8 Ca O + 3 P 2 O; gives 3 (P 2 O s , 

 3KO). 



The solutions a and c, and also that remaining after the precipitation 

 with acetate of lime, were evaporated and heated to redness ; the residue 

 was weighed, and the chlorine and sulphuric acid estimated, and calcu- 

 lated as chloride of potassium and sulphate of potash. By subtracting 

 the two latter salts, and also the potash calculated from the phosphate 

 of lime, from the weight of the whole residue, the quantity of potash not 

 existing as phosphate of potash was obtained. 



Neither of these two methods can be considered accurate in the 

 present day. But as all the analyses were executed according to similar 

 methods, the results are always of value, in so far as they are, to a cer- 

 tain extent, comparable with each other. 



