172 Kansas Academy of Science. 



Analysis of this product shows that the manufacturer has not 

 profited by his former mistakes, but has repeated them all, with 

 one addition — the strawberries have, been left out. 



These products are adulterated and misbranded. The use 

 of the terms "glucose jelly" or "glucose jam" would only par- 

 tially remedy the matter. The use of the term "imitation" 

 would more nearly express the whole truth. To express the 

 whole truth, the truth to which the purchaser is entitled, this 

 word should be followed by some such statement as this, "Made 

 from corn sirup, apple trimmings, strawberries and phos- 

 phates, and colored with a coal-tar dye." 



University of Kansas, Lawrence. 



A METHOD FOR THE DETERMINATION OF STARCH. 



Walter S. Loxg. 



THE METHODS available for starch determinations may 

 be classified under three heads : Polariscopic, reduction, 

 and colorimetric methods. In all polariscopic and reduction 

 methods starch is hydrolyzed to dextrose, and any method 

 of this kind is subject to the errors involved in hydrolysis and 

 in polarization or reduction, as the case may be. These 

 methods, even when most carefully conducted, are incapable 

 of yielding anything like accurate results. The results in- 

 variably come out too low, due on the one hand to the incom- 

 plete conversion to dextrose, on the other to overconversioni 

 giving rise to condensation products having a much less or no 

 cupric-reducing power. As to the accuracy of reduction 

 methods it has been shown by various chemists that in cal- 

 culating starch from dextrose the theoretical value is never 

 obtained, the actual results being from 95 to 98 percent of 

 theory. 



Regarding colorimetric methods it is claimed that "while 

 the methods are short and convenient, the results obtained 

 are only roughly approximate." Several methods have been 

 proposed for the direct estimation of starch, such as precipita- 

 tion with a solution of iodine or barium hydroxide, but none 

 of these methods has yielded trustworthy results. 



In working with such products as jams and jellies many 

 samples were found to contain small amounts of starch — too 

 small for satisfactory determinations by any methods avail- 



