Aqueous Solutions of Acids and Alkalies. 447 



1° the atomic measure is diminished to — 27*66 septems, the 

 condensation effected by 1 test atom being 82*32 septems. 



According to Messrs. Playfair and Joule (Phil. Magazine, 

 vol. xxviii. p. 506), the atomic measure of carbonate of pot- 

 ash in solution is equal to that of water [namely, 16*07 

 septems] . This is correct when the strength of the solution 

 is about 70°, but not under any other circumstances ; since 

 at 400° the measure is twice as much, at 10° the measure is 

 nothing, at 3° it is minus one volume, and at 1° it is minus 

 two volumes. 



The fraction which + 1 indicates the mean specific gravity 

 of 100° of carbonate of potash is (1'2643-f- 18*295 = ) -069106. 



Table XIII. — Anhydrous Soda. 

 NaO =390*897 grs. Temperature 62° F. 



