200 Sir W. Rowan Hamilton on Quaternions* 



The unburnt residue left on evaporation of the fluid in the 

 ascidia of Nepenthes therefore consists, if we take the average of 

 the loss of the three determinations at 31'61 per cent, and reject 

 the carbonic acid of the ash, of — 



Organic matter, chiefly 



Malic acid and a little citric acid . 38*61 



Chloride of potassium .... 50*43 



Soda 6-36 



Lime 2-59 



Magnesia 2*59 



100-57 



It is remarkable that none of the fluids which I examined 

 contained any sulphuric acid, which acid has been found in all 

 juices of plants, and which I do not doubt also exists in the sap 

 of Nepenthes. An ash analysis of this interesting plant would 

 show the proportion of sulphuric acid at once ; and as we are not 

 in possession of an analysis of the ash of Nepenthes, which in 

 other respects might be of interest, I take the liberty of asking 

 those gentlemen who are in the possession of Nepenthes' plants 

 to preserve the clippings of branches, &c., which I shall be glad 

 to receive as materials for an ash analysis. 



XXVII. On Qiiaternions ; or on a New Si/stem of Imaginaries 

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

 M.B.I.A.^ F.R.A.S., Corresponding Member of the Insti- 

 tute of France^ Sfc., Andrews' Professor of Astronomy in the 

 University of Dublin ^ and Royal Astronomer of Ireland. 



[Continued from p. 137.] 



86. nnHE same sort of quaternion analysis, proceeding from 

 -I- the formulae in art. 82*, and from others analogous 

 to them, has conducted the author to many other geometrical 

 theorems, respecting the inscription of gauche polygons in 

 surfaces of the second degree. An outline of some of these 

 was given to the Royal Irish Academy in June 1849; and 

 some of them may be mentioned here. To avoid, at first, 

 imaginary t deformations, in passing from an original sphere, 



* In art. 84, last line of page 135,/or a tangential vector, r<°arf an arbi- 

 trary tangential vector. 



In art. 85, fifth line from foot of page 136, for inscribed polygon of 2»i 

 sides, rearf inscribed polygon of 2vi-\-\ sides. 



f While acknowledging, as the author is bound to do, the great courtesy 

 towards himself that has been shown by several recent and able writers, on 

 subjects having some general connexion or resemblance with those on which 



