OF ARTS AND SCIENCES. 233 



with such the reactions here given were obtained. Baric chloride 

 gives no precipitate alone, but after adding ammonia a colorless salt is 

 thrown down, which is at first flocky, but which soon becomes fine- 

 grained granular-crystalline. Strontic and calcic chlorides behave in 

 a similar manner, but the calcic precipitate does not form so rapidly. 

 Manganous sulphate gives no precipitate alone, but after adding am- 

 monia a white flocky salt is formed, which becomes yellowish on stand- 

 ing. Cupric sulphate behaves in the same manner ; the precipitate 

 after the addition of ammonia is green and flocky. The mixture with 

 solution of copper is not reduced on boiling, either alone or after addi- 

 tion of chlorhydric acid. The solution of the hypophospho-molybdate 

 gives a canary-yellow precipitate with mercurous nitrate, and a nearly 

 white precipitate with argentic nitrate, which soon becomes gray and 

 finally black. Thallous nitrate gives a white flocky precipitate. "When 

 the dry salt is heated, it becomes at first black and fumes slightly, 

 but on further heating it melts to a dark blue mass which gives 

 off a little molybdic teroxide on heating to redness. The fused mas3 

 dissolves readily in hot water, forming a deep blue solution which 

 has an acid reaction, and gives with magnesia-mixture the character- 

 istic ammonio-magnesic phosphate. The effect of heat is represented 

 by the equation 



8 M0O3 . 2 {H, . PO . OH} 2 . (NH,)^ + 2 H,0 = 



8 M0O3 + P2O5 + 3 H2 + 2 (NHJ 2 + H,0. 



In the analyses the loss by ignition corresponds to 2 (NHJ^^ -f~ 

 H.,0 + 3 H.,, and the residual mass to 8 M0O3 + P2O5, when the 

 ignition is made with sodic tungstate. In this salt, — 



1.3172 gr. lost on ignition with W0,Na2 0.1329 gr. = 10.09 % 



II.p, (NH,),0, and H. 



1.0764 gr. lost on ignition with WO^Naa 0.1086 gr. = 10.09 % 



HA (NHJO, and H. 



1.2369 gr. gave 0.1836 gr. NH.Cl = 7.21 % (NHJ^O. 

 1.2850 gr. " 0.0918 gr. (NHJ,0 by titrition = 7.15% 



2.4322 gr. " 0.3860 gr. Pp.Mg^ = 9.42% PO^Hg. 



1.6217 gr. " 0.2578 gr. " = 9.30% PO^Hj. 



The analyses lead to the formula 



8 M0O3 . 2 {H2 . PO . OH^ 2 (NH,), O -f- 2 aq, 



which requires : — 



