AT MAGDALEN COLLEGE 7 



That his' new duties at the Botanical Garden did not lead 

 to the neglect of his chemical teaching or studies is proved 

 by his frequent revision of his lectures, of which the manu- 

 scripts are preserved in the College Library, and by the 

 appearance of a Supplement to an Introduction to the 

 Atomic Theory (1840). Although much time and thought 

 must have been spent upon the buildings and improvements 

 to the Garden already mentioned, yet before two years had 

 passed he had completed a very important research on the 

 Action of Light upon Plants and of Plants upon the Atmo- 

 sphere ; and thus he anticipated Draper by some eight years 

 in demonstrating that the light belonging to the red end of 

 the spectrum is most effectual in promoting the evolution 

 of oxygen by plants. Some of the glass vessels still bear 

 stains of the port wine which was used as a red screen. 



The geological results of his Italian and American journeys 

 in 1834 and 1837-8 were first given to the Ashmolean 

 Society, and many specimens of volcanic rocks were added 

 to his collections. 



In 1 840 the high regard in which his many qualifications Professor 

 were held found expression in his election to a third Profes- 

 sorship that of Rural Economy which he held until his 

 death. 



During the seven years following, his researches were mainly 

 directed to the scientific aspects of certain branches of Agri- 

 culture, and the results were published in several papers in 

 the Journal of the Royal Agricultural Society, his three 

 lectures on Agriculture were even translated for the benefit 

 of Italian farmers. Chief among these chemical agricultural 

 labours were investigations On the Chemical Constituents of 

 Crops, On the Scientific Principles by which the Application 

 of Manures ought to be regulated. On the Use of Spanish 

 Phosphorite, as a Manure. The Memoir on the Rotation of 

 CropS) and on the Quantity of Inorganic Matter abstracted 

 from the Soil by Various Plants under Different Circumstances ', 

 was first delivered in 1845 as the Bakerian Lecture to the 

 Royal Society. 



In his agricultural researches, Dr. Daubeny was no doubt 



