Appendix. 347 



No. 59. 



The following information was kindly given to me by Dr. 

 Murray Thomson, Chemical Examiner to Government, 

 Roorkee. 



" The formula of cane sugar is C 12 H 22 O n , and of Grape 

 sugar C 6 H 12 O 6 H 2 O. The sugar of an unripe orange is 

 chiefly grape sugar, but as the orange ripens, cane sugar 

 appears, and when quite ripe the grape and cane sugar are 

 in nearly equal quantity, viz. about 4*5 per cent of each. 



" The formula for citric acid is C 6 H 8 O 7 . Of course you 

 will understand that this formula is based on the new atomic 

 weights for carbon and oxygen C 12 and O 16 . Oil of lemon, 

 and oil of orange peel are chemically identical. They are 

 hydro-carbons of the group C 10 H 36 ." 



No. 60. 



Prof. Asa Gray, in his " Structural Botany," p. 288, para. 

 545, calls the edges of the carpels "leaf-margins/' as in 

 fig. 618 (caltha palustris) or marsh marigold, and the oppo- 

 site suture he calls midrib. 



In p. 260, para. 478, he says " carpel, or carpophyll denotes 

 pistil-leaves, i.e. seed- bearing or fructiferous phylla (leaves). 

 A carpel may be a pistil of itself, either the only one of a 

 blossom, or one of several, or it may be a constituent of a 

 more complex pistil. In either case, a carpel is the homo- 

 logue of a leaf." 



Para. 479. " The ovules are peculiar structures normally 

 arising as outgrowths from the margins of the leaf, or some 

 part of them ; sometimes from the whole, or a special por- 

 tion of the upper or inner surface of the leaf." 



At p. 299, para. 577, he says, "the Hesperidium (orange, 

 lemon, lime) is the fleshy fruit of a free, many-celled ovary, 

 with a leathery rind, and is a mere variety of the berry."* 



* It would appear to me open to question, whether the Hesperidium 

 ought to be classed with the berries. 



