1 S2 Mr. J. Cockle's Solution of two Geometrical Problems. 



those situated beneath participating in this motion*. The 

 observation of our learned countryman is quite naturally ex- 

 plained by attributing to the ascending sap the transport of 

 the corrosive poison, a transport which, in this case, would 

 take place in the direction from below upwards. But how to 

 account for the apparent transmission of the effects of the 

 chloroform in the contrary direction, from above downwards? 

 Might the descending sap more peculiarly have the property 

 of transmitting the narcotic effects of this singular compound 

 from one part of the sensitive plant to the other ; or might 

 there exist in this plant some special organ susceptible of being 

 affected by certain vegetable poisons in a manner analogous 

 to the nervous system of animals ? Notwithstanding the in- 

 teresting investigations of Dutrochet and other physiologists, 

 there still prevails too much obscurity on this subject to ha- 

 zard an opinion. But in any case the fact is singular, and 

 appears to me to merit the attention of persons accustomed to 

 engage in questions of this nature. 



Experiments of the same kind, made on the contractility of 

 the sensitive plant with rectified aether, have furnished me with 

 results nearly similar to the preceding ; with this difference, 

 however, that whilst one drop of chloroform placed on the 

 common petiole of a leaf situated at the extremity of a branch 

 of a sensitive plant suffices to cause most of the other leaves 

 situated beneath on the same branch to close, aether in general 

 produces an effect only on the leaf itself with which it is put 

 in contact. The next leaves have generally appeared to me 

 not affected. I must however add, that my experiments with 

 aether having been made after the others, and at a time of 

 year when the sensitiveness of the plant already began to di- 

 minish, it is possible that the intensity of the effects produced 

 may have thereby been affected. 



XVIII. Solution of two Geometrical Problems. Py James 

 Cockle, Esq.y M.A., of Trinity College, Cambridge , and 

 Barrister-at-Law of the Middle Temple f. 



THE following solutions are effected by what may be termed 

 a Uniaxal or an Imaginary Geometry. The equations of 

 the problems are formed and treated as if the points which 

 constitute the data and quaesita were in the same straight line. 

 The sketch here given of such a geometry is necessarily short 

 and confessedly imperfect. And yet, perhaps, it will be found 



* DeCandolIe, Physiologie VegHale, vol. ii. p. 866. 

 f Conrinuinicated by the Author. 



