236 ELEMENTARY AGRICULTURAL CHEMISTRY 



For liquids lighter than water a Baum^'s hydrometer is 

 constructed so that in a solution of 1 part by weight of 

 common salt in 9 parts by weight of water it sinks to 0°, 

 while in pure water it sinks to 10°, the scale being extended 

 further up the stem. 



The following formulae connect degrees Baume with true 

 specific gravity : 



For Liquids Heavier 

 than Water. 



At 12-5'' 0. . 

 At 16' O. . 



At 17-5" 0. . 



d = 



145-88 



For Liquids Lighter 

 than Water. 



145-88 



d = 



146-78-n 



d = 



136-78 + n 



Other empiric scales are also in use. The relationships to 

 real specific gravity of some of the principal ones are given 

 below : 



For Liquids 

 Heavier than 



Water. 



For Liquids 



Lighter than 



Water. 



Brix, atl2-5'R. (15-62° 0.) 



Balling 



Gay-Lussac, at 4° 0. . 



Beck, at 12-5° 0. 



Cartier, at 12-5° O. . 



d = 



d = 



d = 



d = 



d = 



400 



126-1 -n 



400 



400 +n 



200 

 200 +n 



100 

 100 +n 



170 



170+71 



13)-^ 

 126-1 +« 



d = true specific gravity. 



n = degrees of the various hydrometers. 



Thermometer Readings. — Though in modern science the 

 Centigrade thermometer is coming more and more into general 



