116 SUGAR BEET SEED. 



question is arranged for polariscopes with dials; the 

 first stop is not far from the zero point, the other is 

 near the division, 30 degrees; the distance between 

 stops is regulated by suitable screws. When once 

 arranged, they are in electric communication with two 

 bells. As each has a different pitch or sound, it is pos- 

 sible under these circumstances to make several classi- 

 fications; for example, below 15 to 16 per cent., or 

 from 17 to 18 per cent., etc. 



If the right or left bell rings, the chemist knows 

 that the juice being examined has a certain sugar per- 

 centage , without it being necessary to do any actual 

 reading. However, careful work demands a certain 

 observation. If, when either bell rings, the disks are 

 neutral, or of some tint depending upon polariscope 

 used, it would show that the stop on the vernier corre- 

 sponded exactly to that percentage; if, on the other 

 hand, the black disc is to the right when the left bell 

 rings, it would show that the juice under observation 

 was of a lower percentage than the limit required for 

 the selection; if to the left when the right bell sounds, 

 this would convey that the sugar percentage was 

 higher than the limit for which it was adjusted. Over 

 1000 observations may be thus made in a very short 

 time and with very little fatigue. 



In the zero, as compared with an ordinary instru- 

 ment, these differences may frequently be 0.2 to 0.3. 

 It is generally desirable to make several observations 

 on the same juice before commencing regular work. 

 After having polarized, the results are noted; during 

 the interval the assistant fills the funnel, etc. The 

 work has twice the rapidity it had with an ordinary 

 tube. In mother-selecting, it is possible to reach ten 

 a minute. Certain difficulties may arise and many 

 precautions are necessary, among which, mention may 

 be made of the following: The liquid being examined 

 must be very clear and ample light must be used ; if the 



