374 Chemical Notices : — M. Scheibler on the Tungstates. 



at low and high tide, Westminster Bridge ; also two samples as 

 supplied by the Chelsea and Lambeth Water Companies. Water 

 supplied by the New River Company; and water from the 

 undermentioned wells : — 



Duck Island Well, St. James's Park. . \ Above the London 



Pump H, Lincoln's Inn J clay. 



Burnett's Distillery, Vauxhall "1 From the sand above 



Whitbread's Brewery, Chiswell Street, j the chalk. 



Guy's Hospital well i cha]k 



1 ratalgar Square well J 



The above waters may be taken to represent the whole of 

 the London supply, since, beside the specimens from the Thames 

 and New River, others from the three principal water-bearing 

 strata of London are included. 



To guard against all possible sources of fallacy, the waters 

 were evaporated in platinum vessels, and all filtration avoided. 

 It need scarcely be mentioned that the alcohol, HO, SO 3 , and 

 HC1 used were free from lithium and strontium. 



LIL Chemical Notices from Foreign Journals, 

 By E. Atkinson, Ph.D., F.C.S. 



[Continued from p. 298.] 



SCHEIBLER has published* an account of researches on 

 the tungstates, with which he has been engaged during 

 the last six years. 



Tungstic acid exists in two distinct modifications — one inso- 

 luble in water (ordinary tungstic acid), and a modification soluble 

 in water (metatungstic acid). And there are two corresponding 

 groups of salts. 



The tungstates, the salts of the insoluble modification, have 

 been repeatedly investigated. The alkaline salts are somewhat 

 soluble in water ; those of the alkaline earths and metals, which 

 are obtained by double decomposition, are insoluble, amorphous 

 or crystalline precipitates. These tungstates are characterized by 

 the fact that, when treated with a stronger mineral or organic 

 acid, a yellow pulverulent or white caseous precipitate of hydrate 

 of tungstic acid is formed, according as the decomposition is 

 effected in the warm or in the cold. To these salts, which have 

 usually been considered acid salts, Scheibler assigns the formula 

 3RO, 7W0 3 -f # Aq, or perhaps more correctly 

 2RO,3W0 3 + RO, 4W0 3 + *Aq. 



* Ber. der Akad. der Wissensch. zu Berlin, April 1860. 



