PAN PROCESS 47 



washed with a thin milk of lime to prevent their rusting 

 until they become thoroughly heated ; the fires are started 

 and the pans are filled by syphons to a depth of about 6 inches 

 with brine from the back pans. The former are so inserted 

 that a constant flow of brine passes from the back pans 

 into the last section of the front pans and from these under 

 the partition into the first section. Into the back pan flows 

 a constant stream from the outside cistern until the front 

 pans are sufficiently full, when the flow is stopped. After 

 a sufficient amount of salt has collected in the first section 

 of the front pan it is removed to the " drip " for drainage. 

 This is called drawing or raking the pans. The front pans 

 are refilled from the back pan, in which the brine has 

 become considerably heated, and thus is prevented a too 

 rapid cooling of the brine in the front pan which would 

 seriously interfere with the formation of a properly grained 

 salt. For the same reason the partition is placed in the 

 front pan since it prevents any cold brine from coming sud- 

 denly into the first section, it being compelled to enter at 

 the bottom of the pan where its temperature is the highest. 

 The first drawing or " drip" usually contain traces of caustic 

 lime in consequence of the white-washing of the pans and 

 since this would be detrimental to butter, cheese, provisions, 

 etc. salted with it, it is always kept separate and sent into 

 the market as "agricultural" salt. 



The following table gives the results of a series of analyses 

 made on the contents of a pan to determine the relative 

 increase of the chlorides of calcium and magnesium and the 

 decrease of sulphate of calcium: 









Calcium 



Calcium 



Magnesium 









sulphate 



chloride 



chloride 



Original bi 

 After runn 







0.3739 P er ct 



0.4714 per ct 



0. 1970 per ct 



ing 24 



lours. . 



0.2658 " 



1.2263 " 



0.3611 " 



" " 



48 



" . . 



0.2009 " 



2.0213 " 



0.6895 



" 



72 



" . . 



0.1819 " 



2.6357 " 



0.9634 " 



" 



96 



" . . 



0.1116 " 



3-3843 " 



I-3I97 " 



" 



120 



" . . 



0.0976 " 



4.9861 " 



1-8343 " 



" 



144 



" . . 



0.0686 " 



6.3569 



3.2316 " 



