OF ARTS AND SCIENCES. 77 



12 : 1 : 4 Sodio-ammonic Tmigstate. — This salt was obtained acci- 

 dentally in an attempt to prepare a series of ethylo-phospho-tung- 

 states. Syrupy phosphoric acid and absohite alcohol were mixed and 

 heated for half an hour to about 80° C, and the mixture allowed to 

 stand twenty-four hours. Ammonia was then added in small quanti- 

 ties at a time until in excess, the liquid being kept cool, the object 

 being to form an ammonic ethylo-phosphate. The solution was then 

 poured into one of 12:5 sodic tungstate. After a few minutes an 

 abundant precipitation took place of small shimmering scales, which 

 were drained on the filter-pump, washed with cold water, then dis- 

 solved in hot water and filtered. A very small quantity of a very 

 insoluble salt in scales remained undissolved. The filtrate soon gave 

 an abundance of small talcose scales with a fatty lustre. 



Of this salt, 



1.0293 gr. lost on ignition 0.1399 gr. = 13.60 % 



1.3019 gr. " " 0.1766 gr. = 13.57 % 



1.0001 gr. gave 0.0618 gr. (Nri,)20 == 6.18 % 



1.0293 gr. « 0.8689 gr. WO3 = 84.46 % 



The analyses correspond to the formula 



12 WO3 . Na,0 . 4 (NHJ2O -}- 14 aq, 



3306 100.00 



No trace of phosphoric acid could be detected in the salt, which is 

 perhaps only interesting as furnishing additional evidence of the 

 existence of a class of meta-tungstates in which the ratio of the tung- 

 stic oxide to the oxygen of the base is as 12:5. In this, as in the 

 16-atom salt above described, the presence of an excess of free am- 

 monia explains the absence of phosphoric oxide in the compound 

 formed. 



My work on the compounds of vanadium is far less complete and 

 thorough than I could have wished, on account of the relatively very 

 high cost of the material. I indulge the hope that what I have done 



