818 Intelligence and Miscellaneous Articles. 



with any defect or deformity of the bones. In three of the cases, 

 the effects symmetrical ; in the fourth confined to one side of the 

 chest. Enormous development of the calves in one of the cases. 



Also a paper was read " On Organic Polarity," by H. F. Baxter, Esq- 



The object of the paper is to show the intimate connexion that 

 exists between organic force and the ordinary polar forces, such as 

 chemical force, for example. 



The principal experiments, showing that organic action, viz. secre- 

 tion, is accompanied with the manifestation of current force, have 

 already appeared in the Royal Society's ' Transactions ' for the years 

 1S48 and 1852; but in the present communication the author 

 enters more minutely into the resemblance between the actions 

 which take place in the voltaic circle and those that occur during 

 secretion than could be prudently attempted in his previous papers. 

 But whatever view may be entertained in regard to the origin of 

 the power in the voltaic circle, whether by mere contact or by 

 chemical action, the decision of this point is of no importance to the 

 question under consideration ; since the manifestation of current 

 force during voltaic action is allowed both by the chemical theorist 

 as well as the contact theorist ; and if we admit the manifestation 

 of this force {current force) to be evidence of polar action in one 

 class of cases, viz. during voltaic action, we are certainly justified 

 in logically concluding that it may be adduced as evidence of polar 

 action in other cases also, viz. during organic action as in secretion. 

 Reference is made to Prof. Graham's researches on osmose. Accord- 

 ing to Prof. Graham, osmose would appear to be dependent upon 

 chemical action, and consequently, should we be disposed to class 

 the phacnomena of secretion with those of osmose, we should be 

 thus compelled to acknowledge that the act of secretion must be 

 polar in its nature. 



The author does not attempt to show in what manner secretion 

 is eftected, his great object being to point out what does occur 

 during this act, viz. the manifestation of polar action, and conse- 

 quently it is upon this ground that we may logically infer that the 

 force must be polar in its nature. 



XXXIX. Intelligence and Miscellaneous Articles. 



ON THE DOUBLE TANGENTS TO PLANE CURVES. 

 BY THE REV. GEORGE SALMON, TRINITY COLLEGE, DUBLIN. 



ONE of the most difficult problems in the theory of plane curves is 

 that of finding the points of contact of double tangents to a curve 

 of the /tth degree. A new solution of that problem may therefore 

 be acceptable. 



The tangent to a plane curve meets the curve in n — 2 points 

 beside the point of contact. If now it were possible to form the 

 equation of a curve of the (n — 2)nd degree passing through those n — 2 

 points, then by forming the condition that the tangent to the given 

 curve should touch this curve of the (« — 2)nd degree, we should im- 

 mediately obtain an equation to be satisfied by the points of contact 

 of double tangents. Now I have succeeded in forming the equation 

 of such a curve of the (?j— 2)nd degree, as follows. 



