944 On the Salts, called Puckwah and Phool-Kharee, [No. 120, 



These 20 parts of dry Sulphate of Soda contain 11.20 of Sulphuric 

 Acid, which require 37.50 parts of Acetate of Barytes to precipitate 

 them. 



5. Now our solution of Acetate of Barytes is made by dissolving 

 100 grains of the salt in 1000 grains of pure water,* and the tube 

 filled to the mark, containing exactly as much of the solution as is 

 equal to 37.50 parts of Acetate of Barytes, the whole of its contents 

 will thus precipitate the 20 parts of dry Sulphate of Soda, which the 

 adulteration of 25 per cent, contains. 



6. And, as it is marked with 25 divisions, each division will shew one 

 per cent, of such an adulteration. As before remarked, a weaker 

 Kharee would allow more adulteration, but as it would shew always a 

 nearly equal quantity of the Sulphate, this may be taken for a standard. 

 I do not believe that a much stronger Kharee could be prepared. Could 

 it be so prepared as to contain 90 per cent, of the Sulphate, this would 

 only make a difference of 2i on the scale in the whole per centage, and 

 for practice nothing beyond proof of, say 10 per cent, of the Sulphate 

 of Soda, is really wanted to be known.f 



7. If we like to take our scale as representing the exact quantity of 

 Sulphuric Acid (which will then be an exact index to the quantity of 

 Sulphate of Soda) we must remember that the 37.50 parts of Acetate of 

 Barytes contained in the tube, are divided by the graduation into 

 26 parts; and as this quantity of Acetate of Barytes is equivalent 

 to [or will precipitate] 11.20 of Sulphuric Acid, we have thus 25 

 divisions for 11.20 of Sulphuric Acid. Every five divisions will then 

 represent 2.24 [or 2^] of Sulphuric Acid, so that we may say in 

 practice, that every 2A divisions of the scale will shew about l^^th part of 

 Sulphuric Acid, or nearly two of Sulphate of Soda : every five divisions 

 representing exactly four parts of the pure Sulphate of Soda ; and five 

 of the adulteration, because of the extraneous salt and water. 



* This solution, at the temperature of 84° is of sp. grav. 1.36, and the Acetate is 

 preferred, because of its cheapness and facility of making it, and because if Muriates 

 or Nitrates are to be sought for, it is not in the way. The Muriate or Nitrate of Barytes 

 may of course be used if desirable, the tubes being graduated accordingly. 



t Here, as before, I need not remark, that a set of careful trials should be made with 

 the Phool-Kharee of various parts to fix a standard. This can only be properly 

 done in the district. 



