XVI. 



OF ARTS AND SCIENCES. 65 



In experiments (80) to (82) and (85) to (88) inclusive there were 

 added to each portion containing the phosphate and tungstate 0.5 gr. 

 of citric acid, hydrochloric acid until the solution became yellow, 

 ammonia in excess and 20 cm. 8 of magnesic chloride mixture ; in ex- 

 periments (83) and (84), and (89) to (91) inclusive, 5 cm. 3 of strong 

 hydrochloric acid (with no citric acid), ammonia in excess and 20 cm. 8 

 of magnesic chloride mixture. The precipitates of (85) to (91) in- 

 clusive were filtered off on paper, washed with magnesic chloride 

 mixture, dissolved in hydrochloric acid and thrown down again with 

 ammonia. The first precipitates of experiments (80) to (84) and the 

 second precipitates of portions (85) to (91) were collected on asbestus, 

 washed, and ignited as usual. 



Mg,P,0 7 . P,0 6 found. PjOg required. Error. ^rror!* 



f (80) 0.0454 gr. 0.0290 gr. 0.0266 gr. -f 0.0024 gr. -f- 9.02 



XI. j(81) 0.04G4gr. 0.0297 gr. 0.0266 gr. -j-0.0031 gr. +11.65 



[(82) 0.0466 gr. 0.0298 gr. 0.0266 gr. +0-0032 gr. -\-l2.0o 



(83) 0.0444 gr. 0.0284 gr. 0.0269 gr. +0.0015 gr. + 5.58 



(84) 0.0447 gr. 0.0286 gr. 0.0269 gr. +0.0017 gr. + 6 -32 



[(85) 0.0405 gr. 0.0256 gr. 0.0270 gr. — 0.0014 gr. — 5.18 



] (86) 0.0414 gr. 0.0265 gr. 0.0270 gr. —0.0005 gr. — 1.85 



j (87) 0.0414gr. 0.0265 gr. 0.0270gr. —0.0005 gr. — 1.85 



1(88) 0.0416 gr. 0.0266 gr. 0.0270 gr. —0.0004 gr. — 1.48 



[(89) 0.0423 gr. 0.0270 gr. 0.0270 gr. 0. 0. 



XIII. "j (90) 0.0424 gr. 0.0271 gr. 0.0270 gr. +0.0001 gr. + 0.37 

 ((91) 0.0430 gr. 0.0275 gr. 0.0270 gr. +0.0005 gr. + 1.85 



In experiments (92) to (101) inclusive 5 cm. 3 of strong hydro- 

 chloric acid were added to each portion containing the phosphate and 

 tungstate. ammonia in distinct excess, magnesic chloride mixture — in 

 (92), (93), (94), and (95) 1.5 cm. 3 and 1.5 cm. 3 more after the pre- 

 cipitate had settled ; in (96) and (97) 2 cm. 3 ; in (98) and (99) 5 cm. 8 ; 

 in (100) and (101) 10 cm. 3 drop by drop and then 10 cm. 3 more at 

 once — and finally after the precipitate had settled, ammonia until the 

 solution evolved a strong ammoniacal odor. 



MgjPA- PA found- PA required. Error. ^rror"*' 



( (92) 0.0424 gr. 0.0271 gr. 0.0269 gr. +0.0002 gr. +0.74 

 j (93) 0.0427 gr. 0.0273 gr. 0.0269 gr. +0.0004 gr. +1.49 



{ (94) 0.0428 gr. 0.0274 gr. 0.0269 gr. +0.0005 gr. +1.86 

 \ (95) 0429 gr. 0.0274 gr. 0.0269 gr. +0.0005 gr. +-1.86 



VOL. XV. (n. S. VII.) 5 



XIV. 

 XV 



