SUGAR, MOLASSES, CONFECTIONS, AND HONEY, 637 



that have the faculty of precipitating themselves on one when he is in a pinch, is the 

 reason for not being more piompt. 



Mr. Horton, \vho has made all of the polarizations and the reducing sugar deter- 

 minations, has had considerable difficulty in bringing some of these substances into 

 a proper condition for examination. This, as you well know, brings vexatious delays. 

 Should you wish any of these determinations repeated we will gladly do it for yon at 

 any time. 



The methods of analyses employed follow. 



Hoping that onr delay has not seriously incommoded you, I am, yours, very truly, 



H. H. NICHOLSON. 

 H. W. WILEY, 



Chief Chemist, Department of Agriculture, Washington, D. C. 



METHODS OF ANALYSIS EMPLOYED. 



Clarification. Very light products use Al-j (OH) 6 . Dark products tannic acid in 

 excess and exact precipitation with a solution of normal lead acetate as in the method 

 proposed by Scheibler. 



Readings. With one or two exceptions all readings made in 2 dcin tube. 



Inversion. 50 cc of solution used for direct polarization, 5 cc HC1 (sp. g. 1. 18). 

 Heated slowly to 70, and kept at this point for ten to twelve minutes, when cooled in 

 stream of water to 17i and filled to mark. Polarized in 2JJ dcm jacketed tube to 

 control temperature. 



Reducing sugar. 5 g in 100 cc, thereby giving burette reading of over 13 cc. 



The inversion work was carefully conducted but the results are not satisfactory. 

 Formerly I heated for fifteen minutes and allowed solution to cool slowly to near the 

 proper temperature, but ten minutes or twelve have been recommended and so I 

 adopted this time limit. You will notice that Dr. Spencer has given this time as 

 ten minutes. 



I have made the following experiments to determine the effect of time : 



I. 50 cc of Sol. 

 5 cc HC1 (1. 18). 



10min.at70. Reading g Series " 



12.10 12.10 



II. 50 cc of Sol. 



5ccHCl(l. 18). 



15 min. at 70. Reading j^rjes. j3 Series. 



11.52 11.48 



Difference 0.58 0.62 



I am at present carrying through samples giving fifteen minutes as recommended 

 and hope to find some interesting results. 



Sirups, molasses. Clarification, inversion, readings, reducing sugars as with sugars. 



I have been amazed at the high right-hand ] -izatio" of these sirups. The num- 

 ber obtained are to a certain extent inaccurate, as we uad the Schmidt & Haeusch 

 instrument to work with. In every case where the high polarization was found the two 

 halves of field of vision in instrument were tinted and not light and shadow, pointing 

 conclusively to presence of substances having different power of refrangibility from 

 quartz or sugar. In inversion these solutions did not color as did solution having 

 approximately + 50 polarization, but could be read without any preparation. 



The color and viscosity of these ultra right-hand sirups are characteristic. 



From a few observations I think that dextrin in the sirups is the cause of the high 

 numbers. 



Honeys. In examining the honeys I have used 26,048 g to 100 cc, and have ob- 

 tained perfect clarification with Al.. (OH) B . 



