1905.] On the Germination of Seeds of the Castor Oil Plant. 77 



solution, therefore, a little ether was added, drop by drop, till a faint 

 turbidity was apparent. 



After standing in this condition for some days, a crop of aggregates of 

 crystals separated out. When dissolved in water they were found to have 

 a specific rotatory power of about « D = + 66. After inversion with a dilute 

 mineral acid the specific rotatory power became about « D = —18. The 

 solution of the crystals gave no crystalline osazone on warming with 

 phenylhydrazine acetate. 



These reactions are fairly conclusive that the non-reducing sugar is cane- 

 sugar. 



The reducing sugar was refractory and no method succeeded in rendering 

 it crystalline. It was also found impossible to separate it completely from 

 the cane-sugar, so that its specific reducing power could not be obtained. 

 Eeadings with the polarimeter were unsatisfactory on account of its proving 

 impossible to free its solutions from a yellow colouration. When the latter 

 were warmed with phenylhydrazine acetate they yielded a quantity of a pale 

 yellow osazone which analysis proved to be the osazone of a hexose. After 

 several recrystallisations from alcohol and from ethyl acetate the crystals 

 were found to have a constant melting point at 204° C. This is consistent 

 with the view that it is invert sugar produced from the cane-sugar with 

 which it is associated. It negatives the hypothesis put forward in the 

 former paper that it is derived from the glycerine of the fat, for this sugar 

 (glycerose), now much more completely investigated, is known to yield an 

 osazone melting at 130° C. to 131° C * 



The occurrence of two sugars exhibiting the characters just described 

 suggested a search for invertase among the constituents of the endosperm. 

 A good number of well germinated seeds were selected, having most of the 

 endosperm absorbed; the embryos were well developed, their root system 

 considerably branched. The endosperms were removed and ground up into 

 a paste, which when strained through muslin yielded 95 c.c. of an acid sap. 

 This was carefully neutralised and a little antiseptic added. It contained 

 a quantity of both reducing and non-reducing sugar, 10 c.c. of the sap 

 reducing 0*2 gramme of cupric oxide. Tubes were prepared containing 

 respectively 10 c.c. of the neutralised juice with 10 c.c. of a solution of the 

 non-reducing sugar from the seeds, and 10 c.c. boiled juice with the same 

 quantity of the sugar solution, and they were digested in a water-bath at 

 40° C. for several hours. On titration the weight of cupric oxide reduced by 

 the digestion containing unboiled juice was 0'31 gramme while the other 



* Fischer and Tafel, ' Ber. d. deut. Chem. Ges./ vol. 20, p. 1088 ; Fenton and Jackson, 

 ' Trans. Chem. Soc.,' 1899. 



