Dr. Hugo Mold, on Liebig's Organic Chemistry. 99 



tion of carbonic acid, is untrue. The assertion that plants neither 

 absorb organic substances, nor assimilate them, rests on mere 

 theoretical speculation, and is destitute of all proof. The statements 

 as to the relation borne to the atmosphere by plants in the dark is 

 in direct opposition to every fact bearing on the subject. The asser- 

 tion that the nitrogenous food of plants, and that which contains no 

 nitrogen, are absorbed in certain proportions, is uncorroborated 

 by the analysis of either the seed or the full-grown plant. The 

 theory of the rotation of crops is contrary to experience, and 

 unsound in its details. The assertion that plants receive their food 

 during summer from the atmosphere alone, is incorrect. 



On the other hand, it cannot be denied that Liebig's idea that 

 plants derive their nitrogen from the ammonia of the atmosphere is 

 very happy and pregnant with results. It is also probable that the 

 absorption of saline bases is in direct ratio to the power of saturation 

 of the acids formed in plants. These two views are a real gain 

 to science, and it may be expected that his work will also have the 

 merit of exciting others to make correct experiments on the nutrition 

 of plants. But he has endeavoured to introduce into vegetable phy- 

 siology a series of most erroneous notions, and his unbecoming out- 

 breaks against other physiologists have proved him to be very little 

 acquainted with the subjects on which his book is written. — From 

 the Gardeners' Chronicle for 1843. 



Fourteenth Meeting of the British Association for the Advancement 

 of Science. York, September 25. 



The General Committee assembled on Wednesday, at two o'clock, 

 and the chair was taken by the Earl of Rosse. The minutes of the 

 two last Meetings held in Cork, were read and confirmed. 



The Report of the Council was then read, on the results of the 

 applications made to Government pursuant to the recommendations of 

 the General Committee at the Cork Meeting. It was stated that 

 application had been made to the Master General of the Ordnance, 

 for aid in conducting experiments on captive balloons, and that he 

 had issued instructions to the Commandant at Woolwich, to afford 

 every facility for the purpose. A resolution had been adopted at the 



