1280 Wisconsin Academy of Sciences, Arts, and Letters . 
Whitehead has suggested a remedy in the use of sodium acid 
sulphite. He advises a moderately concentrated solution of the 
sulphite and that the quantity added to the tellurium solution 
he sufficient only to just neutralize the acids present and that 
formed during the reaction. When the solution is thoroughly 
agitated and then allowed to stand in a warm place, the precipi¬ 
tate will form and settle evenly. He states that “while sodium 
acid sulphite does not completely remove all of the tellurium 
from the solution in the cold, that if not used in great excess 
and the mixed solutions he raised to the boiling point, toward 
the end of the action the precipitation will he perfect, and the 
tellurium will be obtained in a state of aggregation favorable to 
easy filtration.” 
Frerichs has worked on the basis that hydriodic acid and sul¬ 
phur dioxide cause immediate and complete separation of tel¬ 
lurium from a tellurous solution even in the cold, and Mclvor * 1 
has confirmed this method. 
Horris and Fay 2 have demonstrated that under ordinary work¬ 
ing conditions precipitated tellurium increases in weight about 
0.5 per cent, owing to oxidation and that this increase is bal¬ 
anced by the quantity of the elements left behind as tellurium 
tetrachloride in the strongly acid solution in which the precipi¬ 
tate was formed by sulphur dioxide. They believe that it is 
more accurate to weigh tellurium dioxide than to weigh tellu¬ 
rium in the elementary state. 
Mclvor 1 and Donath 2 have studied the precipitation of tel¬ 
lurium by hyposulphurous acid. This method possesses the dis¬ 
advantage of a precipitate of tellurium contaminated by more 
or less sulphur. The method hardly possesses any advantages 
over the sulphurous acid percipitation. 
Stolba 1 in 1873 and later Kastner 2 have proposed the precipi¬ 
tation of tellurium from an alkaline solution by means of grape 
sugar. 
1 Chem. News 87, 163. 
2 Amer. Chem. Jr. 20, 278. 
1 tuem. News 87, 163. 
2 Zeit. fur Angew. Chem., 1890, 214. 
1 Zeit. fur Anal. Chem. 11, 437. 
2 Zeit fur Anal. Chem. 13, 142. 
