MICKOSCOl'ICAL EXAMINATIONS OF FRUITS, K'J < . 105 



in apple butter, where the cells were well separated from each other, 

 the starch was found to l>e much more abundant inside than outside 

 the cells. In making this test a small amount of rather strong iodine 

 solution (iodine, 1 gram; potassium iodide, "2 grams; water, 300 cc) 

 should be used, else a considerable diluting effect will occur. 



Adams' 1 gives Hoffman's violet (Dahlia), followed by iodine, as a 

 color test for apple pulp, claiming that the stain for apple is very dif- 

 ferent than that obtained for other fruits. Although we have tried 

 the aqueous and anilin water solution, the color has not been found 

 sufficiently characteristic to be reliable in most cases. What at lirst 

 seemed to be characteristic differences on closer work were found to 

 be caused by differences in the sugar or acid content, which served to 

 mask or vary the normal staining effect. 



Malfatti b has gone quite carefully into some of the anatomical 

 characteristics of apple and pear, but as he eontined his efforts largely 

 to features of the epidermis, capsule walls, and seeds parts usually 

 removed in preserved goods the differences are obviously of little 

 value where the pulp alone is used. In the table at the end of this 

 article the effort has been made to bring together in concise form the 

 leading morphological and chemical characteristics of some of the 

 fruits most like apple in the pulp condition to assist in the identifica- 

 tion of apple when present. 



A careful histological study of the seeds of those fruits in which the 

 entire fruit is used will aid greatly in their identification. Marpmann ' 

 has worked out certain histological features of the seeds of tigs, 

 raspberries, currants, gooseberries, whortleberries, blackberries, straw- 

 berries, and elderberries which characterize these species and assist in 

 their identification. Since A. L. Winton, of the Connecticut Experi- 

 ment Station, had already begun a careful histological study of various 

 fruits, no further detailed work of that nature was undertaken in con- 

 nection with this bulletin. 



The writer became identified with the Bureau of Chemistry after the 

 chemical work described in Part I was completed and the samples dis- 

 carded. It was therefore impossible to apply these methods to those 

 samples, as it was not deemed advisable to procure new samples of the 

 same goods on account of the press of work in other fields. 



PREPARATION OF SAMPLE. 



To prepare the sample for microscopical examination a portion, after 

 being warmed with several times its bulk of water, is shaken up suffi- 

 ciently to free the particles from sugar and allowed to settle. If the 

 sample is finely pulped the settling process can be greatly hastened 



'Analyst, 1884, 9, 101. 



"Xtschr. Xahr. Ily-. 1S<K, 10, !><*, L>*7. :n:i, .Sl>9. 

 -. aiijr. Mikros., II Bd., 4 Ih-ft. 



