264 AQUEOUS SOLUTIONS—MACGREGOR. 
smaller volumes than their constituent water would in the free 
state possess. In the case of the phosphate, this is true of all 
solutions containing less than about 0.016 per cent. of the 
anhydrous salt, the difference of volume being greatest in solu- 
tions containing about 0.011 per cent. A solution of this 
strength, containing 1000 cubic inches of water, has a volume of 
999.87 cubic inches. In the case of the carbonate I found the 
greatest difference of volume to occur with a solution containing 
about 0.026 per cent. of anhydrous salt, a solution of this strength 
which contained 1000 cubic inches of water having a volume of 
998.27 cubic inches. 
