EXAMINATIONS OF APPLE STARCH. 89 



phite treatments in method for cellulose) amounts to but 3.87 per cent 

 of the dry marc." 



The pectin removed during the first hour of boiling was soluble in 

 water. It yielded 46.58 per cent of pentosan and 54.6 per cent 

 " starch "(*) and showed a rotatory power of [ai] D =71.2 to 78.7; i. e., 

 a 1.851 per cent solution polarized at 3.8 to 4.2 in a Schmidt and 

 Haensch polariscope in a 10-cm tube. The pectin removed during 

 the second hour gave 41.46 per cent of pentosan and 30.02 per cent 

 " starch." It was impossible to get a solution clear enough to polarize. 

 No mucic acid determinations were made. 



Whether pectin in apple marc is a series of bodies of similar consti- 

 tution but of different degrees of hydration, or whether it is a mixture 

 of bodies of different kinds, was not determined. This could be found 

 out by examining, by the criteria of yields of reducing sugar on hydro- 

 lysis with acid, pentosans, and mucic acid, the portions obtained by 

 fractional extraction with boiling water from the tissue and by a simi- 

 lar examination of the products resulting from fractional precipitation 

 of the water extract with alcohol. It is hoped that such studies may 

 be made. 



III. MICROSCOPIC AND MACROSCOPIC EXAMINATIONS OF APPLE 



STARCH. 



MICROSCOPIC STUDIES. 



SIZE OF STARCH GRAINS. 



The presence of starch in apples is in itself no new consideration. 

 Buignef in his work upon the apple failed to find starch present, 

 although the filtered juice from green fruit was colored blue with iodin, 

 which phenomenon was accredited to the presence of tannin. Accord- 

 ing to Lindet/ the earliest mention of starch in apples was made by 

 Grignoiv* in 1887. Lindet himself describes the general features con- 

 cerning the disappearance of the starch, and gives as the size of the 

 grains 6 to 20 microns. 



An examination of the starch as it normally occurs in the tissues 

 will show that the grains are generally compounded, being composed 

 of from 2 to 5 simple grains. In preparing samples of apple starch, 

 the grating of the flesh usually results in tearing these compound 

 grains apart, so that grains having a truncated form very greatty pre- 

 dominate, as is shown in Plate I. 



"That is, 43.20 per cent was insoluble in 1 per cent sodium bydroxid and 39.33 

 per cent of cellulose was obtained, so that 3.87 per cent was removed by the treat- 

 ments with chlorin and sodium sulphite. 



& See footnote c, page 88. 



'J. phar. chim., 1859, (3) 30: 81-111. 



<*Ann. agron., 1894, 20: 5-20. 



<>Le Cidre Doin. 



