( 3�) 

SODIC PINATE AS A TEST FOR LIME. 

By J. A. SEWALL. 

Pinic acid or sodic pinate precipitate salts of calcium, magnesium 
and iron. 

I have recently made some experiments with the sodic pinate, with re­
ference to its delicacy as a test for detecting the presence of the salts of the 
first mentioned metal (�alcium \ with the following results, using a solution 
of calcic sulphate : 

25\,.0 part of calcic sulphate in one part of water, yields a very copious 
amorphous precipitate, which readily subsides. 

50\rn part yields an abundant bulky precipitate. 
To1nnr part, an abundant precipitate. 
� part, an immediate cloudiness, and in a few minutes a good 

precipitate. 
� part, quite the same result as is given by the 2rlo7r solution. 
1 2 510 0 0 part, a very satisfactory deposit after a little time. 
2 5 01

0 0 0 
part, a distinct turbidity, and after a few hours a satisfactory 

deposit. 
I observe that on adding a few drops of the reagent to distilled water, 

the solution becomes, after several days, slightly opalescent. 
The reagent was prepared by dissolving one part of the sodic pinate in 

fifteen parts of distilled water and filtering the solution. 
The quantity of the solution of the calcic sulphate operated on in each 

trial was one fluid ounce. The quantity of the sodic pinate solution used in 
each trial varied from two to ten drops, the larger quantity being used in the 
stronger solution of the' calcic salt. 

Ammonic oxalate fails to precipitate lime in a n½oo solution, (Fre­
seni'us). 

It will be seen from th� above that the sodic pinate is a much more 
delicate test for calcic salts than the ammonic oxalate. The deportment 
of other calcic salts is quite the same as that of the sulphate.