22(j 



Dried at 212". 



Carbon . . 26.58 



Hydrogen . 2.86 



Oxygen . . 25.97 



Oxide of lead 45.3G 44.59 



100.00 



The tribasic salt gives 



Dried at 212". 



Carbon . . 21.89 22.07 



Hydrogen . 3.06 2.82 



Oxygen . 23.75 23.73 



Oxide of lead 52.30 51.38 



100.00 100.00 



651.1 100.00 



If we consider the xanthorhamnine, as dried in the oil- 

 bath, to be then anhydrous, the bodies analyzed become 



Xanthorhamnine, dry = C23 H12 O14. 



do. dried at 212°. = C23 H,2 Oh + Aq. 



do. dried in vacuo = C23 H12 Ou + lSAq. 



1st lead salt, C23 H12 Oh + 2. PbO + 3 Aq. 

 2nd lead salt, C23 H,2 Oh + 3 PbO + 6 Aq. 



The xanthorhamnine is thus formed by the addition of 

 one equivalent of water and two of oxygen to the chry- 

 sorhamnine, as C23 HuOn + HO + O2 = C23H,2 0h. And 

 if we were to consider the substance dried in the oil-bath at 

 320° still to retain an atom of water, it should be simply 

 oxidated chrysorhamnine, being, when dry, 



C23H„0„+2 0. 



The Rev. H. Lloyd, V. P., read a supplement to a former 

 communication " on a New Magnetical Instrument, for the 

 measurement of the Inclination and its Changes." 



