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EXTRACTS FROM THE JOURNALS. 



NUTRITION OF PLANTS— LIEBIG'S THEORY. 



Dr. W. Seller has communicated to the Royal Society of 

 Edinburgh, his examination of the views adopted by Liebig, on 

 the Nutrition of Vegetables; for the purpose of determining how 

 far these are just, and with what limitations they require to be 

 received. 



The following propositions represent the spirit of the opinions 

 on which Dr. Seller comments: — 



1st. That the food of plants is strictly of a mineral or inor- 

 ganic nature. 



2d. That ammonia, carbonic acid, and water impregnated with 

 a few saline matters, are the sole aliments of plants. 



3d. That the organic matter of soils must pass into the mineral 

 state, namely, into water with a saline impregnation, carbonic 

 acid and ammonia, before it can become subservient to the uses of 

 vegetation. 



4th. That the saline matters and the like, which form the ashes 

 of plants, are, without exception, taken up from the soil, and are 

 in no respect the product of vegetation, as was taught in the be- 

 ginning of the present century. 



Thus the maxims adopted by Liebig on the nutrition of plants 

 are of a negative character; for if it can be shewn that the doc- 

 trine of the nutrition of plants by organic compounds in the soil 

 is unfounded, then the truth of Liebig's grand axiom, as to the 

 mineral nature of the food of plants, is established at once. 



We have not space to quote (from Jameson's Journal, No. 77) 

 the arguments by which Dr. Seller seeks to refute these views. 

 The following, alDridged from the close of this valuable contribu- 

 tion to science, is highly important: — 



The spirit in which De Saussure so long since studied the ve- 

 getable economy, appears to have become dormant among bota- 

 nists for a good many years. They had too little faith in the 

 conclusions of modern chemistry to trust to it as an instrument of 

 research. Nor was it surprising, at the commencement of this 

 century, when chemistry was hardly beyond its infancy. 



Chemistry, in short, must always be the very groundwork of 

 vegetable physiology. It must teach the number, the properties, 



