or, 



OF ARTS AND SCIENCES. 123 



0.7672 gr. gave 0.6278 gr. W0 3 -f P 2 8 = 81.83% 



1.5557 gr. lost on ignition 0.1872 gr. water = 12.03% 



1.3732 gr. lost on ignition 0.1641 gr. water = 11.95% 



1.6196 gr. gave 0.1547 gr. S0 4 Ba = 6.27% BaO 



and 0.0581 gr. P 2 7 Mg 2 = 2.29% P 2 5 



1.2094 gr. gave 0.1158 gr. S0 4 Ba = 6.28% BaO 



The analyses agree fairly well with the formula 



24 W0 3 . P 2 0. . 3 BaO . 3 H 2 + 43 aq, 



W 24 P 2 O n (Ba0 2 ) 3 (HO) G + 43aq. 



The same salt is formed when two atoms of 12 : 5 sodic tungstate are 

 boiled for a time with two atoms of sodic phosphate and chlorhydric 

 acid is added in excess. Baric chloride then gives after a time crys- 

 tals exactly similar to those described above. In a salt prepared in 

 this manner, — 



1.0020 gr. gave 0.8173 gr. W0 8 + P 2 6 = 81.56% 



1.4718 gr. gave 0.1648 gr. S0 4 Ba = 6.97% BaO 



and 0.0518 gr. P 2 7 Mg 2 = 2.25% P 2 O s 



1.4841 gr. lost on ignitioa 0.1717 gr. water = 11.57% 



Calc'd. Mean. 



24WO s 5568 79.57 79.57 79.69 79.46 



P 2 5 142 2.03 2.12 2.14 2.10 



3 BaO 459 6.56 6.62 "§h 6.28 6.97 



46 H 2 828 11.84 11.78 12.03 11.95 11.57 



#6977 100.00 100.09 



The phosphoric oxide determinations are corrected in both analyses. 

 The percentage of baric oxide as determined by difference, which is 

 the more accurate method, is 6.53. The salt effloresces with extraordi- 

 nary rapidity, so that it is very difficult to dry it for analysis by pres- 

 sure between folds of woollen paper. 



Twenty-two Atom Series. — The phospho-tungstates containing 22 

 atoms of tungstic oxide to 1 of phosphoric oxide are represented by 

 apparently well-defined salts of potassium, sodium, and ammonium. 

 I have not succeeded in preparing the corresponding acid. As already 

 stated, Scheibler has given provisionally the formula 



H i 8 pw i As + 18 H 2 0, or 22W0 3 .P 2 O s .6H 2 + 45aq, 



