CIN'TI HORTICULTURAL SOCIETY— PROCEEDINGS. 



;C0NTINUKD FEOM PaGE 188. ) 



Even Schleiden, held good as authority — a man who had worked 

 with hand and eye, and had called to his aid the habitual use of the 

 microscope, and investigated the laws of vegetable economy most 

 assiduously, so that it would seem that if any one could tell truly all 

 that could be observed, it were he — still Schleiden is full of errors, 

 and has often been proved so. He said what he did not know. He 

 teaches what others taught, but what no one ever knew, and could 

 not know, because they were not true, hence he is contradicted by 

 later writers, and his errors shown. And Schleiden like the true 

 philosopher that he is, came boldly forth, and, over his own signa- 

 ture, admitted his errors, and all because he neglected the rule to say 

 no more than he knew. On the same principle we must here be 

 firm in exposing our error whenever detected. For instance, it was 

 said and written that the roots of trees and plants excreted certain 

 substances which are found as original secretions in the texture of 

 the plant, as potassium, etc., all founded on the experiment of put- 

 ting one root into a solution of a lead, and another of the same plant 

 into pure water, when it was found that some portion of the poison- 

 ous lead was carried over and impregnated the pure water. But it 

 was soon found that so far from this being the result of organic ex- 

 cretion, it was simply produced by capillary attraction on the surface 

 of the roots, and when this medium was effectually cut off", the pure 

 water remained free from any infusion of the lead. So with Ehren- 

 BURGH, with regard to his Infusoria, in which he fancied that he had 

 found muscular power and organic functions, such as prehension and 

 dit^estion but which, ere long, were discovered to be not animal, but 

 vegetable developments — vegetative growths in diff"erent ages or stag- 

 es of development. Science demands that in attempting to teach, we 

 must say what we know, and as to what we read and do not know, 

 let it always be presented with a mark of interrogation. And, said 

 Mr. Ward, he is a friend indeed who corrects another when in error. 

 Mr.WARD then read from Mr. Cary on " The Root," that "a root 

 does not turn green on exposure to the air." Now, asked he, does 

 he know that ? Others have proved that when exposed the root does 

 turn green and does not die, but may present all the external 



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