114 PROCEEDINGS OF THE AMERICAN ACADEMY 



18:1 : 2 Ammonic 3Iono7netaphospho-tung state. — When 12:5 am- 

 nionic tuugstate is boiled with a solution of glacial phosphoric acid, a 

 white crystalline mass remains undissolved, very different in appear- 

 ance from the ammonic tungstate employed. This salt requires a 

 large quantity of boiling water for solution, but is only slightly soluble 

 in cold water. For analy.-is, it was thoroughly drained upon the filter- 

 pump, and then washed with cold water. Of this salt, 



1.G89G gr. lost by ignition with WO^Naj 0.1082 gr. = 6.40^^ 

 1.5026 gr. gave 0.0745 gr. P.O-Mgs = 3.17% P2O5 



1.4267 gr. " 0.0316 gr. (NH4)20 =2.21% 



The analyses correspond to the formula 



18 WO3 . 2 {PO3NH,} . (NH,)20 + 11 aq, 



which requires : 



4620 100.00 



The filtrate from this salt gives on evaporation a thick colorless 

 syrup, in which white crystals — perhaps of the salt above described — 

 were suspended. It will be seen that the action of PO3H upon 12:5 

 ammonic tungstate is essentially the same as upon the 10:4 potassic 

 salt, and that in each case at least one crystalline and one gummy 

 salt are formed. 



The analyses given are sufficient to establish the existence of three 

 classes of monometaphospho-tungstates. My work on this subject is 

 to be regarded merely as preliminary, and is intended to direct the 

 attention of other chemists to this class of salts. In another paper I 

 shall give the results of a more detailed study of the various meta- 

 phospho-tungstates. Fleitmann and Henneberg have described five 

 series of metaphosphates ; in addition to these, there remain to be 

 studied, in their relation to tungstic and molybdic oxides, the two series 

 of tetraphosphates, P4O- . 6 RO, and dekaphosphates, Pi„Oj^ . 12 RO, 

 discovered by the same chemists, as well as the new group of salts 

 described by Salzer,* which may be called hypophosphates. 



* riiarmaceutische Zeitung, Bunzlau, 1881. Ann. der Chemie, ccxi. 1. 



