On Current Furce in Lacteal Absorption and Nutrition. 37 



layers of diiFerent mineral composition to be formed in such a 

 manner as to produce a cleavage, without there being any cry- 

 stalline polarity. Such an alternation along planes analogous to 

 slaty cleavage, as well as that similar to stratiiication, does indeed 

 occur to a certain extent in some rocks, so far metamorphosed as 

 to have become foliated, as I described in a paper at the late 

 meeting of the British Association at Glasgow, on the older rocks 

 of the Scottish Highlands. However, when not thus metamor- 

 phosed and foliated, unaltered cleavage is seen by the microscope 

 to be a fracture through homogeneous rock, independent of any 

 such alternation of layers of diiFerent mineral composition ; and 

 therefore I conclude that this cleavage-foliation no more proves 

 simple slaty cleavage to be the result of crystalline agencies, 

 than does stratification-foliation indicate that they gave rise to 

 stratification. 



Summing up now the general facts contained in this paper, I 

 show that, other circumstances being the same, the cleavage of 

 the limestones varies directly as the amount of mechanical com- 

 pression to which they have been subjected ; and that the effect 

 of this is such as would necessarily change the structure of un- 

 cleaved into that which occurs in those that are cleaved. Also^ 

 that cleaved limestones possess no crystalline polarity; and that, 

 in place of crystallization producing slaty cleavage, it has a con- 

 trary tendency, and when perfect and complete obliterates it 

 altogether. Though inorganic deposits do not present us with 

 such decisive facts, yet I am persuaded that their slaty cleavage 

 may be satisfactorily explained on similar principles, and that 

 they agree, not only with what may be seen with high powers 

 of the microscope, but with the structure of mountain masses. 

 Can I therefoi-e hesitate to conclude that slatij cleavage is the 

 result of mechanical and not of crystalline forces "i 



IV. An Experimental Inquiry undertaken with the view of ascer- 

 taining whether the organic actions, Lacteal Absorption and 

 Nutrition, in the living Animal are accompanied with the mani- 

 festation of Current Force. By H. F. Baxter, Esq."^' 



THE following series of experiments, an abstract of which 

 has already appeared in the Proceedings of the Royal 

 Society (Nov. 25, 1852), form a continuation of an inquiry in- 

 stituted for the purpose of ascertaining whether organic actions 

 in the living animal may not be accompanied with the manifes- 

 tation of electrical action. Having arrived at the conclusion in 

 a former scries f, that the organic process of sea-etion in the 

 * Communicated by the Author, 

 t Phil. Trans. 1848, 1852. 



