262 BISULPHATE OF SODA, ETC. 



PREPARATION OF THE BISULPHATE OF SODA. 



The ordinary commercial article is not sufficiently pure for 

 use, and I prepare it from pure carbonate of soda or sulphate 

 of soda that has been purified by recrystallization. In either 

 instance pure sulphuric acid is added in excess to the salt in a 

 large platinum capsule, and heated over a flame until the melted 

 mass, when taken up on the end of a glass rod, solidifies quite 

 firmly. The mass is then allowed to cool; moving it over the 

 sides of the capsule will facilitate this operation. When cool 

 it is readily detached from the capsule, then broken- up, and put 

 into a glass-stoppered bottle. So far as my experience has yet 

 gone, in almost every instance where we have been in the habit 

 of using bisulphate of potash, the bisulphate of soda can be 

 substituted. 



