262 BUTTER-MAKING. 



siuni chloride. It is known positively that the presence of this 

 substance in salt, even to a small extent, imparts a bitter flavor 

 to butter. Salt containing a large amount of this and other 

 impurities also absorbs moisture from the air more readily 

 than does pure salt. According * to analysis of the best dairy 

 salt in use in Denmark, the composition is as follows : 



Pure salt 97.49 



Magnesium chloride 18 



Gypsum .05 



Sodium sulphate 21 



Water 2.07 



100.00 



The purest American dairy salt has the following composi- 

 tion : f 



Pure salt (NaCl) 99. 18 



Magnesium chloride (MgCl2) 05 



Gypsum (calcium sulphate, CaS04) , .54 



Calcium chloride (CaCl2) 19 



Insoluble matter 03 



Moisture 01 



100.00 



In order to judge the quaUty of salt the butter-maker 

 cannot rely on the chemical analysis for a detection of im- 

 purities, but must judge the quahty from its appearance 

 flavor, and odor. Good dairy salt does not have a dark -bluish, 

 coarse, granulated appearance, but a clean, white, silky look, 

 and should dissolve quickly. Salt should be kept in a clean 

 dry place free from odor. 



* Boggild, Maolkeribruget, Denmark, 

 t Bui. No. 7-i, Wis., by F. W. Woll. 



