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to prescribe the general Rules and Principles which shall regulate 

 their distribution hereafter. The King has therefore commanded 

 that they shall be adjudged annually, and that the award shall be 

 announced on the day of the Anniversary Meeting of the Royal 

 Society; that the Memoirs which shall be entitled to receive them, 

 whether composed by Foreigners or by Englishmen, shall be com- 

 municated to the Royal Society; and that the general subject matter 

 of such Memoirs shall be prescribed and announced by the Council 

 at least three years preceding the day of their award : and also, that 

 for the present and the two following years, the principle of their 

 distribution shall be the same as that which has hitherto been adopted, 

 with the additional condition, that the succession of branches of sci- 

 ence which shall be selected as entitled to these rewards, shall be the 

 same as that which shall be hereafter followed when the cycle of 

 their regular distribution begins. 



The selection of the subjects which should compose this cycle was 

 left to the Council of the Royal Society, who have made such a 

 choice as seemed to them best calculated to comprehend every de- 

 partment of science and to prevent the jealousies which might arise 

 from the recurrence of similar subjects in immediate or too close 

 succession : the subjects themselves and their periodical order (de- 

 termined by lot) are as follow : — 



1. Astronomy. 



2. Physiology, including the Natural History of Organized Beings. 



3. Geology and Mineralogy. 



4. Physics. 



5. Mathematics. 



6. Chemistry. 



In conformity with these Regulations, which form the existing 

 law for the distribution of the Royal Medals, they have been awarded 

 for the current year to Professor de Candolle, of Geneva, for his 

 numerous and valuable researches and investigations in Vegetable 

 Physiology, as detailed in his Work, entitled " Physiologie Vegetale," 

 published in the year 1832; and to Sir John Frederick William 

 Herschel, for his Paper "On the Investigation of the Orbits of Re- 

 volving Double Stars," inserted in the Fifth Volume of the Memoirs 

 of the Royal Astronomical Society. 



The science of Vegetable Physiology has at all times presented 

 extraordinary difficulties, and although it has employed the talents 

 and the industry of a great number of philosophers, from the earliest 

 period, little progress has been made in obtaining an exact knowledge 

 of the minute organization of plants, and of the mode in which their 

 functions are exercised, at least, when compared with the great ad- 

 vance which has taken place in the analogous sciences which relate 

 to the comparative anatomy and physiology of animals. 



The structure of vegetables, in consequence of its minuteness and 

 intricacy, is involved in the greatest obscurity ; its investigation re- 

 quires the application of powerful microscopes, and is liable to all the 

 fallacies peculiarly incident to such observations : and the greater 

 part of vegetable physiology being dependent on the full and accurate 



