192 Dr. A. Voelcker on the Chemical Composition of the 



and when /=1, Ai = a,5 where a^ and a^ are the values of a 

 from the first of (6.). 



By means of these we easily find the other particular inte- 

 grals. Let them be hci = bj{^)j Ai=6,/j(9). We shall find 

 that,/(fi) and/,(fl) are infinite at the pole, and therefore inad- 

 missible. Consequently we must have 63=0, 6i=0, and 



A2=«2(^l+2cos2-j _, A,=ai 



cos- 



^2= \ -^ (sin ^Aa), Bj = ;^ (sin flAO 



(8.) 



2 f/e ^ 2y» --1 ^g 



where the values of Bg and B, are derived from the second of 

 (a.), and the arbitraries a^ and «j are functions of r. It is to 

 be observed that in making Sw a complete variation relative to 

 6 and vs only, and not to r, we shall lose no terms depending 

 on r\ for the arbitrary of the integral, not containing cr, and 

 therefore not <p, must be rejected. And it is to be further 

 observed, that there are no more solutions than that obtained. 



Gunthwaite Hall, near Barnsley, Yorkshire, 

 July 28, 1849. 



[To be continued,] 



XXVI. On the Chemical Composition of the Fluid in the Ascidia 

 o/'Nepenthes. By Dr. A. Voelcker of Frankfort*. 



THE watery secretions of certain plants belonging to the genera 

 Nepenthes, Cephalotus, and Sarracenia, have long attracted 

 the attention of botanists ; but whilst the secreting organs of these 

 plants have been minutely described, the chemical nature of the 

 fluid itself has been but very imperfectly examined. That these 

 liquids have not met with the attention to which their importance 

 entitles them, may be accounted for by the circumstance that few 

 chemists have an opportunity of obtaining the imaltered fluids, 

 and that even those who are fortunate enough to procure them, 

 seldom can command a sufficient quantity to enable them to inves- 

 tigate their nature. With the exception of Dr. Turner's analysis 

 of the fluid in the ascidia of Nepenthes, I know of no other ana- 

 lysis of this fluid or of similar secretions. The botanists who 

 have given attention to the subject of the watery secretions of 

 the leaves of plants have found these secretions to consist in most 

 cases of nothing but pure water, and have only occasionally dis- 



* From the Annals and Magazine of Natural History, 2d Series, vol. iv. 

 p. 128. 



