THE DETERMINATION OF CANE SUGAR 



495 



some portion of the stem above the level of the liquid. The Brix h\'drometer, 

 which is generally used, is so constructed that the degree indicated at the 

 point where the level of the liquid cuts the stem indicates the soUds in 

 solution referred to a sucrose basis. 



The principle of graduation of the hydrometer is as follows : — The 

 weight of liquid displaced by the floating instrument is equal to the weight 



Fig. 329 



of the instrument. Let w be the weight of the hydrometer and let v be the 

 volume of the portion immersed. Then d=w jv where d is the specific 

 gravity of the solution, and v=w jd. For a series of specific gravities, 

 t;j =Wildi, V2 = w^jd^, fg = w^/ds and if d^ ^= d2 -{- c = d^ + 2 c etc., 

 where c is small v^ = V2 -\- x = v^ + 2x nearly. 



Hence, for a restricted range the scale on the spindle will be divided 

 into equal portions for each increment in specific gravit}' or for each degree 

 BrLx. 



