360 
Proceedings of Royal Society of Edinburgh. [sess. 
The Reciprocals of these numbers are, in order, 
2151 
2257 
2344 
2439 
2522 
2212 
2317 
2404 
2492 
2581 
2268 
2375 
2460 
2551 
2640 
Comparing with the formula, we see that these reciprocals 
should be, in the first column proportional to II, II + 1, II + 2 ; in 
the second to II -I- 5a?, II + l+5x, 11 + 2 + 5a?; etc., where x is 
the increase of II for 1 part sugar in 100 (by weight) of water. 
The results are not very concordant, especially in the second and 
fifth columns (which seem to indicate some error in the gauging of 
the corresponding piezometers), but they are all fairly satisfied by 
taking 
II: 1 \x = 2151 : 58T : 19*2; 
so that the actual value of II appears to be 37 tons’ weight per 
sq. inch. 
Thus it appears that the effect of sugar is, weight for weight, 
barely one-third of that of common salt in reducing the compressi- 
bility of water; for, with common salt, x=l nearly. 
