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Monday, 4th April 1853. 

 Sir T. M. BRISBANE, Bart., President, in the Chair. 



The following Communications were read : — 



1. On Nitric Acid as a source of the Nitrogen found in Plants. 

 By Dr George Wilson. 



The author, after referring to the opinions of those who contend 

 that plants derive their nitrogen only from ammonia, shewed, in 

 justification of the belief, that they also derive that element from 

 nitric acid : — 



Firstly, That nitrates are largely offered to plants, both as they 

 grow wild, and as they are artificially cultivated. 



Secondly, That plants do not refuse the nitrates thus offered to 

 them. 



Thirdly^ That the nitrates which enter plants do not, if properly 

 diluted, do injury to any class of them. 



Fourthly, That nitrates largely promote the growth of the most 

 important plants. 



Fifthly^ That as chemists are at one in regarding the chief function 

 of a plant, considered as a piece of chemical apparatus, to be the de- 

 oxidation of those oxides, such as water, carbonic acid, and sulphuric 

 acid, which enter it, they cannot with any consistency deny that nitric 

 acid, which is one of the most easily deoxidised of all oxides, must, 

 more easily than the oxides referred to, part with its oxygen, and 

 give up nitrogen to the plant. 



Sixthly, That although it would be unwise to be dogmatic on the 

 phenomena which occur within the recesses of a plant, or to affirm 

 that it cannot derive nitrogen from many sources ; yet, according 

 to the present conclusions of science, it may be reasonably urged, 

 that the simplest chemical expression which we can give to our 

 belief regarding the source of the nitrogen which is so important 

 to plants, must be, that the inorganic or mineral representative and 

 parent of all the nitrogenous constituents of plants, and through them 

 of animals, is neither ammonia alone, nor nitric acid alone, but the 

 compound of both, i. e., nitrate of ammonia. 



