278 Sir W. Rowan Hamilton on Qjiaternions, 



Potash .... 40-28 



Soda 0-92 



Lime 18-97 



Magnesia . . . 8*74 



Sesquioxide of iron 0'80 



Chloride of sodium 0-82 



Phosphoric acid . 23-24 



Sulphuric acid . . 5-10 



Silicic acid . . . 1-13—100-00 

 The preceding analyses furnish a new confirmation of the 

 fact first observed by De Saussure, namely, that the largest 

 amount of mineral constituents is deposited in those parts of 

 the plant in which the process of assimilation appears to be 

 most active. While the ash left by the root, stem, fruit and 

 seed did not exceed from 3 to 4 per cent., the leaves left 

 not less than 13 per cent, of fixed residue on incineration. 



Regarding the composition of the different ashes, the great 

 amount of carbonic acid found in the ashes of the root, the 

 stem, and the fruit is at once obvious ; proving that not only 

 the fruit, but also the roots and stem, contain a large quan- 

 tity of organic acids. 



From the composition of the ashes of the root, the stem, 

 and the leaves, the orange-tree belongs decidedly to the lime 

 plants. In these three ashes the joint amount of lime and 

 magnesia exceeds the quantity of the rest of the mineral con- 

 stituents. In the ashes of the fruit and seed, however, the 

 alkalies are as prevalent as they have been found in analogous 

 cases. The amount of phosphoric acid (23-24) in the ash of 

 the seed is considerable, as might be expected, still it is in- 

 ferior to the quantities (34'81 and 42-02) which Mr. Souchay 

 found on analysing the seeds of the citron [Citrus Medico) 

 and quince-trees [Pyrus Cydonia). Nevertheless the ash of 

 the orange-seed is very analogous in composition to the ashes 

 of the last-mentioned seeds, as may be easily seen on com- 

 paring their analysis *. 



XLVI. On Qjiaternions ; or on a New System of Imaginaries 

 in Algebra. By Sir William Rowan Hamilton, LL.D., 

 V. P.R.I, A. i F.R.A.S., Corresponding Member of the Insti- 

 tide of France,) Sfc., Andrews^ Professor of Astronomy in the 

 University of Dublin j aiid Royal Astronomer of Ireland, 

 [Continued from p. 219.] 

 37. 1)ESUMING now the quaternion form of the equa- 

 -*■*' tion of the ellipsoid, 



(«p + H'-(/3f-p/3)^ = l> (1.) 



• Liebig's Annals, liv. p. 343. 



