262 BUTTER-MAKING. 



slum 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 : | 



Pure salt (NaCl) 99. 18 



Magnesium chloride (MgCl 2 ) 05 



Gypsum (calcium sulphate, CaS0 4 ) , . 54 



Calcium chloride (CaCk) 19 



Insoluble matter 03 



Moisture.. .01 



100.00 



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

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

 purities, but must judge the quality 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. 74, Wis., by F. W. Woll. 



