132 PROCEEDINGS OF THE AMERICAN ACADEMY 



This salt was obtained by boiling 12 : 5 sodic tungstate with half its 

 weight of phosphoric acid. After a short time the salt separates in 

 beautiful crystals. As Scheibler's salt evidently belongs to a 6-atom 

 series, and has therefore a special theoretical interest, I endeavored in 

 various ways to prepare it, but in all cases without success. By boil- 

 ing 12 : 5 sodic tungstate with half its weight of phosphoric acid I ob- 

 tained a thick sirupy liquid, wbich after long standing gave crystals. 

 In another experiment about 75 gr. of the sodium salt were boiled with 

 13 gr. of sirupy pure phosphoric acid. After dilution and standing for 

 some days, splendid colorless prismatic crystals separated, identical in 

 appearance with those of the last experiment. These were redis- 

 solved and recrystallized several times. Of this salt, — 

 0.5551 gr. gave 0.4272 gr. W0 3 + P 2 5 = 76.95% 



0.5787 gr. " 0.4459 gr. " = 77.06% 



1.5430 gr. " 1.1884 gr. " =77.02% 



1.0058 gr. « 0.0980 gr. P 2 7 Mg 2 = 6.35% P 2 6 



1.0285 gr. " 0.1014 gr. " = 6.34% " 



1.0023 gr. " 0.3214 gr. P 2 O n U 2 = 6.38% " 



1.0152 gr. lost on ignition 0.1656 gr. water == 16.31% 



1.0240 gr. " " 0.1677 gr. " =16.37% 



0.9922 gr. " " 0.1612 gr. " = 16.24% 



These analyses correspond fairly well to the formula 

 14 W0 8 . 2 P 2 4 . 5 Na 2 -f- 42 aq, 

 which requires : — 



The phosphoric oxide, which was twice precipitated, is too high, 

 but it may be that in such salts a third precipitation is necessary to 

 effect a perfect separation. I should write the formula of the salt, 

 provisionally, either, , 



6 W0 3 . P 2 O s . 3 Na 2 . 3 H 2 + 8 W0 3 . P 2 5 . 2 Na 2 . 4 H 2 -f- 35 aq, 

 or, 

 6 W0 3 . P 2 5 . 2 Na 2 . 4 H 2 + 8 W0 3 . P 2 6 . 3 Na 2 . 3 H 2 + 35 aq. 



There appears to be no reason for distributing the sodic oxide in one 

 way rather than in the other. On the other hand, it is perhaps equally 



