30 DK. SCHLEIDEJJ'S THEORY OF AGraCULTURE. 



III. — Dr. Schleidens Theory of Agriculture. By the Rev. 

 M. J. Berkeley, M.A., F.L.S.* 



The volume before us, whose full title we have given below, 

 may either be considered as a distinct work in itself, or as a 

 single volume out of three, constituting a cyclopaedia of theoretic 

 natural history for the use of agriculturists, comprising physics, 

 inorganic and organic chemistry, meteorology, mineralogy, 

 geology, the knowledge of soils and manures, the physiology of 

 plants and animals, and the theory of rational husbandry. It is 

 not our intention to advert to that part of it which relates to the 

 physiology of plants and animals ; it is to the third part only 

 that we purpose to direct the attention of our readers, premising 

 that in the prospectus issued by the publishers it is considered so 

 complete as to render any more especial rules of husbandry un- 

 necessary, inasmuch as the principles involved are so clear and 

 certain as to enable every one who has any interest in the matter 

 to apply them at once as any particular case may arise. While, 

 therefore, it modestly proclaims itself merelj' as theory, it in 

 point of fact professes itself as thorougiily practical. 



It is in this point of view, therefore, that we think a fair 

 abstract, conveyed as mucii as possible in the words of the 

 author, may prove not uninteresting nor unsuggestive of practical 

 good, though we are not prepared at once to adopt the views of 

 the learned author, which are greatly at variance with many 

 notions which are generally current amongst cultivators. Dr. 

 Schleiden, though often paradoxical, is always an able reasoner ; 

 and whatever we may think of his new theory of the impregnation 

 of plants, he has so many titles to merit as an excellent anfl 

 acute observer, that whatever he advances is entitled at least to a 

 candid examination. 



The main position amidst others of various degrees of import- 

 ance contained in the theory of the cultivation of plants is simply 

 this, that manures do not act immediately on vegetation by 

 means of their organic contents, but by reason of the inorganic 

 substances which they involve. The organic portions, however, 

 perform a part absolutely necessary to the process, as they retain 

 the inorganic portions in their tissues, and by their power of 

 absorption of matters contained in the surrounding atmosphere 

 render them available for nutrition. 



* Die Physiologic der Pflanzen und Thiere uiid Theorie der Pflanzen- 

 cultur fiir Landwiithe bearbeitet von Dr. M. J. Schleiden, Professor an der 

 UniversitUt zu Jena. Braunsweig, 1850. 8vo., pp. 490 & xii. rait 1.54 in 

 den Text eingedruckten Holzschuitten. 



