21 



CHEMICAL COMPOSITION. 



M. Payenstecher observes that the fruit of neither 

 pears nor apples assume a blue colour when treated 

 with iodine, shewing that they do not contain 

 starch. It is obvious, from the black colour struck 

 when they are cut with a knife, that they contain 

 also tannin, or gallic acid, or both. They contain 

 likewise pectic acid and malate of potash. The fer- 

 mented juice of apples is called cider. It is specifi- 

 cally heavier than water, assumes a brown colour 

 when concentrated by evaporation, and deposits a 

 blackish-brown powder, and leaves a thick brown 

 syrup. Cider contains alcohol, incrystallizable sugar, 

 gum, extractive, malic acid, bimalate of potash, ma- 

 late of lime, a trace of phosphate of lime, and of sul- 

 phates and muriates. {Thomson s Vegetable Chem, 

 892.) 



Mr. Solly has made some slight examinations of 

 several varieties of the apple, the results of which 

 appear in the following table. The column exhibit- 

 ing the quantity of organic matter in each may be 

 considered, probably, as a true statement of their re- 

 lative nutritive qualities. In which case the Golden 

 Harvey is the most nutritious, and the Court of Wick 

 the least so. 



