BUTTER. 



293 



perceived. This unevenness injures the quality, and 

 causes the butter to deteriorate very rapidly, because a 

 large portion of it is not affected by the salt, which re- 

 mains nndissolved, and cannot exercise its desired anti- 

 septic action. Moreover, the salt is impure, as is shown 

 by the arrow-head crystals, which are evidently sulphate 

 of lime, a common impurity in a poor quality of salt, 

 which gives a bitter taste to the butter, and causes 

 white spots to appear in it. The bitterness is probably 

 caused by the formation of sulphate of soda (Grlauber's 



Fig. 54.— BUTTEB NOT PROPERLY SALTED. 



salt), and the white spots by chloride of calcium, both 

 being produced by the reaction of the dissolved sulphate 

 of lime, and the chloride of sodium (salt), in the butter. 

 The white spots with a dark center are no doubt caused 

 by the action of this chloride of calcium upon the butter; 

 an evidence of this may be found by testing a little of 

 the same with a small fragment of this substance. 



When the butter is freed from excess of moisture by 

 this action of pressure above described (and this method 

 is important to be observed), it is ready for packing and 

 should be packed at once. Every minute's exposure to 



