220 PHYSIOLOGICAL BOTANY. 



empty spaces, is readily understood ; but they are, in 

 most cases, filled with some subtile matters, as air, heat, 

 &c. The membrane of organic bodies allows fluids to 

 permeate it ; in endosmosis this is probably effected by 

 electricity. In the living body, these pores appear to 

 open and close an effect of the vital force, which in 

 many other cases manifests itself to us by contraction and 

 expansion. 



Schleiden completely follows Fries in his philosophical 

 views, and has written a pamphlet against Hegel and 

 Schelling, in which he states that he does not attack their 

 system, but merely endeavours to show their ignorance of 

 natural science. The followers of these two philosophers 

 might find much to censure in it, as, in my opinion, 

 would the followers of Fries also, in his illustration and 

 application of the philosophy of Fries. I consider myself 

 as rather belonging to the latter ; but this is not the 

 place to discuss the matter. The author does not men- 

 tion Oken, who certainly deserves consideration. How- 

 ever, I will not give rise to a dispute, which under 

 the present circumstances could not prove of any advan- 

 tage to science. 



Scientific disputes are usually beneficial to the pro- 

 gress of science. They not only augment the interest of 

 science itself by producing novelty in its monotonous 

 course, but they also possess the advantage of causing 

 the disputant to develope the grounds upon which his 

 opinion is based, more fully, for the sake of more clearly 

 illustrating it and convincing his opponent. Whether 

 he succeed in the latter or not, must be left undecided 

 by the disputant ; but so much is certain, that if this is 

 not immediately or very shortly the case, one or the other 

 ultimately acquires conviction. The advantage which 

 would result from the development of the grounds for or 

 against any view vanishes, when mere contradiction 

 i. e. rejection without a reason is made use of. It pro- 

 duces the least advantage to science when the dispute is 

 carried on with a truly original rudeness, as is generally 

 done by Schleiden. 



