144 Repokt of Department of Animal Industry of the 



For C6Hi4027P6Mg5 = 825.5 



Calculated Mg 14.71: P 22.53 per ct. 



Found Mg 14.69: P 21.99 per ct. 



For 24 H2O Calculated 34.36: found 33.91 per cent. 



HEXA-CUPRIC PHYTATE. 



This salt is precipitated directly from phytic acid solutions by copper 

 acetate. It is difficult, however, to obtain a pure compound as it 

 is apt to contain either too little or too much copper, depending 

 upon the conditions under which the precipitate is formed. In the 

 purification of phytic acid it is usual to remove other bases which 

 are present by repeatedly precipitating with barium chloride; the 

 barium salt which is finally obtained is then decomposed with sul- 

 phuric acid. It is found, however, that if only the calculated quantity 

 of sulphuric acid is used the barium sulphate which is formed is 

 in an extremely fine condition which it is impossible to remove com- 

 pletely either by repeated filtrations or even by day-long centri- 

 fuging. But if a slight excess of sulphuric acid is used the barium 

 sulphate in the course of only a few hours becomes heavy and gran- 

 ular and may be easily removed by simple filtration. In order to 

 get rid of the excess of sulphuric acid the solution is now precipitated 

 with copper acetate. The copper salt can be easily washed free 

 of the sulphate and acetate with water as it is very slightly soluble 

 in very dilute acids. The pure copper salt is then easily decomposed 

 with hydrogen sulphide and the free phytic acid obtained. 



The copper phytate obtained from such slightly acid solutions 

 was analyzed and the following results obtained: 



For CeHiaOzyPeCue = 1083 

 Calculated Cu 35.18: P 17.17 per ct 

 Found Cu 33.54: P 16.88 per ct. 



Pure phytic acid in water was precipitated with pure copper 

 acetate when a compound was obtained which had the following 

 composition : 



Cu 37.57: P 15.13 per ct. 



It is seen from above that from slightly acid solutions of phytic 

 acid a copper salt is precipitated which contains somewhat too little 

 copper while from an aqueous phytic acid solution a salt is obtained 

 which contains over 2 per ct. excess of copper. 



The copper phytate is, like all other phytates, exceedingly soluble 

 in 10 per ct. phytic acid. It dissolves readily until a thick heavy 

 syrup is formed, but it was found impossible to bring this solution 

 to crystalHzation. Both of the above copper salts show an acid 



