524 Prof. A. H. Churcli on certain Ethylphosphates. [Dec. 8, 



mixed ferric and alumiuic chlorides upon argentic ethylphosphate, several 

 salts were obtained of constant as well as of definite composition. For in 

 tKe majority of experiments where the same or slightly varied proportions 

 were employed, the same compound was obtained, even where but a very 

 small portion of the new compound, compared with the quantity formed, 

 was allowed to separate or be precipitated. This observation applies to 

 the salts obtained by ebullition and evaporation, by precipitation with 

 alcohol, and by the action of the mixed ferric and aluminic chlorides upon 

 the argentic ethylphosphate. 



When the proportion of aluminium to iron in the mixed ethylphosphates 

 ranged near the ratio 13*7 : 84, the salt first formed gave on analysis results 

 corresponding to the formula 



UP0,+3Aq. 

 Al i 



In an analysis where both Al and Fe were determined, the following 

 results were obtained : — 



1'056 grm. gave -241 grm. Fe^Og, and '0515 grm. Al^Og. 

 A comparison of these results with theory gives — 



Theory. Experiment. 



Percentage of Fe 16-04 15-97 



Percentage of Al 2-62 2-51 



When the ratio 27 '4: 56 was attained, there was no difficulty in obtain 

 ing a salt having the formula 



Fe, l3PO,+3Aq. 

 Al. J 



In one analysis 



•83 grm. gave '1305 grm. Fe^Og, and -081 grm. Al^ O3. 



A comparison of these results with theory gives- 

 Theory. Experiment. 



Percentage of Fe 11-18 11-01 



Percentage of Al 5-38 5-21 



But on further increasing the proportion of aluminium to iron up to 

 41*1 : 28, no other definite compound could be obtained, though the salt 



Fe 

 AI3 



might be reasonably supposed to exist. Yet the two compounds obtained, 

 if from their constancy of composition when prepared in diverse manners 

 (volumetric determinations of iron in both salts were made with nearly 

 the same results as those just given) I am justified in deeming them definite 

 salts, not mixtures, may lead one to conclude the formula for the ferric 

 ethylphosphate 



3PO, + 3Aq 



