38 



C. P. Wilson stated that he was not entirely satisfied with the results because with 

 the apparatus he used he found it necessary to dissolve the fat before removing it from 

 the flask in which it was recovered by the extraction. 



C. I. Lott: In order to secure evidence with regard to the accuracy of the sampling, 

 analyses were made of three bottles (A, B, and C) of each paprika. The discrepancies 

 in the determination of the iodin number were attributed partly to differences in the 

 amount of extract obtained occasioned by the removal of different amounts of the 

 difficultly soluble resins and partly to errors in the process of determining the iodin 

 number. It was suggested that possibly in the earlier determinations the extract was 

 not completely dissolved in the chloroform preliminary to the Hanus solution. In 

 the later determinations special effort was made to secure a complete solution. With 

 this precaution the following results were obtained: Pure paprika, 116.7, 117.7, 115.1; 

 paprika with olive oil, 116.1, 116.1, 117.6. Further experiments are needed to ascer- 

 tain whether or not a better agreement of results can be secured by observing special 

 precautions in dissolving the extract. 



CONCLUSIONS. 



The radical difference in the results reported by the different analysts in the deter- 

 mination of nonvolatile ether extract and the iodin number of the extract may be in 

 part explained by differences in the extraction apparatus employed and in the rate 

 of extraction, some of the analysts securing an extract which contained a much greater 

 amount of resins than that obtained by the others, which resins have a much lower 

 iodin number than the fatty oil. This explanation, however, does not account for 

 many of the differences. For example, Messrs. Woods and Lott obtained practically 

 the same percentages of nonvolatile ether extract in the pure paprika, but one reports 

 an average iodin number of about 80 and the other of about 115. On the other hand, 

 Mr. Wilson obtained the highest percentage of nonvolatile ether extract, and Mr. 

 Brinton the lowest, yet both secured practically the same results on the iodin number. 



The results reported indicate either that the method of securing the nonvolatile 

 ether extract for the determination of iodin number is seriously at fault, or else spe- 

 cial precautions, yet to be determined, are necessary to the success of the process. 

 The results are not only widely discrepant, but they fail to throw any light whatever 

 on the question of adulteration. 



RECOMMENDATIONS. 



It is suggested that during the ensuing year the following methods be studied: 

 First, extraction on filter paper, with ether, as followed by Doolittle and Ogden,a 

 and, second, shaking for a definite time with a definite volume of ether and evapora- 

 tion of a portion of the filtered extract. It is believed that satisfactory results can be 

 obtained only by a purely conventional method, using the same weight of material, 

 the same volume of ether, and the same time of extraction. It may be found impor- 

 tant, however, to use such portions of the ether solutions as will yield in all cases 

 approximately the same amount of nonvolatile ether extract. The results obtained 

 in the determination of alcohol extract throw no light on the question of added oil. 



REPORT ON COLORS. 

 By H. M. LOOMIS, Associate Referee. 



The work of the past year has been chiefly on the identification of colors. For this 

 purpose twelve samples of colored food products were prepared in the laboratory, 

 using the purest colors available, and samples of each were sent to six cooperating 

 chemists. It is only just to state that many of the colors used were not furnished as 

 food colors -by the manufacturers. In this work the endeavor has been to prove that 

 the colors used were simple commercial colors, and not mixtures, without special 

 regard to the presence of mineral salts, etc. 



^ J. Amer. Chem. Soc. 1908. 30: 1481. 



