438 M. Stromeyer on Polyhalite. [Dec. 



iron, which are equal to 0-004 grm. of red oxide ; therefore, the 

 entire quantity of red oxide contained in the mineral which I 

 analyzed amounted to 0-024 grm. 



g. The solution, being afterwards heated until it boiled, and 

 during this process precipitated by carbonate of soda, yielded 

 1-970 grm. of carbonate of lime ; but 100 parts of carbonate 

 ofhme converted into sulphate by means of sulphuric acid 

 yielded, according to our experiments, 134-69 parts of anhydrous 

 sulphate of lime 5 therefore, the quantity of carbonate of lime 

 arising from this solution is equal in weight to 2-6534 grms. of 

 anhydrous sulphate of lime. 



h. Lastly, when I perceived that the alkaline liquor was not at 

 all deturbated by boiling, I precipitated it by muriate of barytes 

 acidulated with muriatic acid. The sulphate of barytes thus 

 deposited, being properly collected and edulcorated after igni- 

 tion, was found to weigh 4-524 grms. 



Therefore the entire quantity of sulphate of barytes obtained 

 from this analysis of polyhahte was 6-497 grms. {b) + 4-524 

 grms. = 1 1-063 grms. which, according to the calculation before 

 given, affords 3-7615 grms. of sulphuric acid. Therefore 7'247 

 grmg. of polyhahte, when thus examined, presented 



Grammes. 



Anhydrous sulphate of lime (c, d, and g). . 3-2619 

 Anhydrous sulphate of magnesia (d) .... 1-4750 



Sulphate of potash 1-9935* 



Red oxide of iron (e and/) 0-0240 



6-7544 



Therefore, the proper calculations being made, 100 parts of 

 polyhalite are found to contain 



Anhydrous sulphate ofhme 45-0103 



Anhydrous sulphate of magnesia. . . 20-3532 



Sulphate of potash 27-4817 



Red oxide of iron 0-3311 



93-1763 

 (E.) 



This analysis being repeated with 5-921 grm. of polyhalite, 

 there were found 



Grammes. 



Anhydrous sulphate of lime 2-635 



Anhydrous sulphate of magnesia 1-155 



Sulphate of potash 1-634 



Red oxide of iron . 0-018 



5-442 

 * From sulphuric acid computed 1 '95$ grm. 



