BUREAU OF CHEMISTRY. 429 



worm-eaten and decayed olives in the shipments inspected was at- 

 tributed to the practice of gathering and packing culls and windfaUs, 

 while the wormy, decayed condition of the figs was undoubtedly due 

 to the methods used in preparation and packing. A noticeable 

 improvement in the quality of the late shipments resulted, evidencing 

 the exercise of more care in the selection of the fruit and the methods 

 of gathering and packing. 



During the past year a large number of samples of canned vege- 

 tables and fish have been examined for the presence of tin. Notable 

 amounts of the salts of tliis metal were often lound mLxed with the con- 

 tents, the same having been dissolved from the surface of the container. 

 This work involved the selection of a method for the determination of 

 tin which would be both expeditious and accurate, the procedures in 

 common use being found lacking in both these respects. 



In connection vnih the inspection of paprika and ground red 

 pepper the study and detection of the adulterants commonly used 

 has been continued. The refractive mdex of the nonvolatile ether 

 extract of a large number of samples has been determined. The 

 results indicated that when the conditions of drying the extract are 

 pro])erly controlled the refractive index as well as the iodin number 

 will furnish evidence in the detection of added oil. As a result of 

 collaboration of several chemists with the associate referee on spices, 

 a provisional method for the detection of added oil in paprika was 

 adopted in 1910 by the Association of Official Agricultural Chemists. 

 In preparing the better grades of paprika only the shells and part of 

 the seeds are used, the stems and placenta being removed. In order 

 to utUize these by-products they are sometimes added to the cheaper 

 grades, and as the addition of extra stems unquestionably injures the 

 quality of the finished product it has been the practice to subject 

 samples to careful microscopical examination in order to detect this 

 sophistication. 



The question of loss by evaporation on shipments of cloves entering 

 Into interstate commerce having arisen, certain experiments were 

 undertaken by this laboratory upon the cloves as imported to deter- 

 mine the per cent and nature of this loss. Representative samples of 

 cloves as imported were secured, put up in wooden boxes holding 

 from 1 to 4 pounds, and allowed to stand under conditions similar to 

 those followed by the spice grinders and spice trade, and the loss in 

 weight determined after standing varying periods of time. Chemical 

 analyses of the samples were also made for further information in 

 determining the character of this loss. 



In connection with the inspection of spices a large number of deter- 

 minations of the ash of various varieties of black pepper and cayennes 

 were made to ascertain the variations as to the normal ash content 

 of these products. 



Colors. — The enforcement of the provisions of Food Inspection 

 Decisions Nos. 76 and 77 has entailed a large amount of original work, 

 both as regards the analysis of dyes offered for certification and the 

 identification of colors found in foods. During the year improved 

 methods of estimating Orange II in Orange I have been elaborated and 

 methods for the quantitative separation of the seven permitted dyes 

 as they occur in certified mixtures have been worked out. A scheme 

 for the identification and separation of the oU-soluble colors has also 



