538 Mr. W. J. Young. Hexosephosphate formed by [July 30, 



is much more susceptible to the action of phosphoric acid. On the other hand, 

 these low ratios may be due to the presence of some other reducing substances 

 having a less laevorotatory power than fructose. 



Salts of Hexosephosphorie Acid. 



In addition to the lead salt already described, several other salts have been 

 prepared. Attempts to obtain the potassium and sodium salts were made by 

 adding the hydrates to the acid solution until neutral to phenolphthalein, and 

 evaporating the solution under reduced pressure. A sticky mass was left 

 which would not crystallise, and which decomposed on keeping. 



Solutions of the alkali salts slowly decomposed on keeping, free phosphate 

 being formed and the solution becoming lsevorotatory. This decomposition 

 causes a small error in the estimation of the free phosphate present in 

 a mixture of this salt and hexosephosphate by means of magnesium citrate 

 mixture. Many of the salts are more soluble in cold than in hot water ; 

 thus, when magnesium citrate is added to a solution of sodium hexose- 

 phosphate, no precipitate is formed until the mixture is heated ; a white 

 precipitate then comes down, which redissolves on cooling. The manganese, 

 barium, and calcium salts behave in a similar manner. 



Silver Hexosephosphate, C<jHio04(P04Ag 2 ) 2 .— This salt was obtained by 

 neutralising the free acid with caustic soda, adding the calculated quantity of 

 silver nitrate and then half the total volume of alcohol. The precipitate was 

 filtered off, well washed with a mixture of water and alcohol, dehydrated 

 with alcohol and ether, and dried over sulphuric acid in a vacuum, and it was 

 thus obtained as a white amorphous powder. It was exceedingly unstable, 

 and the whole preparation was carried out by red light. Even when dry the 

 salt darkened on exposure to light, whilst when heated with water it was at 

 once reduced to metallic silver. 



The following analyses were carried out with different preparations of this 

 salt : — 



Table X. 



Origin. 



Weight 

 taken. 



AgCl. 



Mg 3 P.D 7 . 



Percei 

 Ag. 



itages. 

 P. 



(2) 



„ (2) 



-2340 

 -3976 

 -3293 

 -3214 



-1740 

 -2989 

 -2439 

 -2378 



0-0644 

 -1057 

 -0893 

 -0909 



55 -94 



56 -54 

 55 -75 

 55 -70 



7-67 

 7-40 

 7 "55 

 7-87 





56 -24 



8-08 



