86 



Anniversary Meeting. 



[Nov. 30, 



are facts of the highest significance, which he has been the first to indicate, 

 and which in many cases he has also proved by observation and by experi- 

 tnents. We refer to his observations on the development of the reproduc- 

 tive bodies of the three orders of Thallogens (Algse, Lichens, and Fungi), 

 and on the conversion under peculiar conditions of certain forms of their 

 fruit into others ; — to the exact determination of the relations, and some- 

 times of the absolute specific identity of various forms of Fungi previously 

 referred to different tribes ; and to the recognition, in many species and 

 genera, of a diversity of methods of reproduction in giving origin to parallel 

 series of forms. As intimately connected with the life-history of Fungi, the 

 intricate subject of vegetable pathology has been greatly elucidated by him ; 

 and he is indeed the one British authority in this department. His inti- 

 mate acquaintance with vegetable tissues, and with the effects of external 

 agents, such as climate, soil, exposure, &c., has enabled him to refer many 

 maladies to their source ; and to propose methods, which in some cases 

 have proved successful, of averting, checking, and even curing diseases in 

 some of our most valuable crops. In this line of research he has also 

 demonstrated, on the one hand, that many so-called epiphytal and parasitic 

 Fungi are nothing but morbid conditions of the tissues of the plant ; on the 

 other hand, that microscopic Fungi lurk and produce the most disastrous 

 results where their presence had been least suspected. 



Mr. Berkeley, 



I present yoa with this^Medal, in testimony of the high opinion which 

 the Botanical Members .of the Council of the Royal Society entertain of 

 your researches in Cryptogamic Botany, especially Mycology ; in which 

 latter department your writings entitle you, in their judgment, to be con- 

 sidered as the most eminent living author. 



The Council has awarded a Royal Medal to John Peter Gassiot, Esq., 

 for his researches on the Voltaic Battery and Current, and on the Discharge 

 of Electricity through Attenuated Media. 



These contributions, most of which are recorded in our Transactions, are 

 of high value, and in some respects peculiar. Their experimental part has 

 been conducted on a scale of magnitude and power unmatched since the 

 days of Davy and of Children, with apparatus of the highest perfection, and 

 with consummate dexterity and skill ; and the discussion and interpretation 

 of the facts observed are characterized by sound theory and sober judgment. 



It would trespass too much on your time were I to give a detailed ac- 

 count of them, and I shall only select a few which are examples of what 

 Bacon has called '* Instantise Crucis," such as, when the mind is undecided 

 between several paths, point out the true one. 



1 . The first decides a question which was long debated with great ve- 

 hemence, whether the energy of the Voltaic Battery arises from the contact 

 of its metals, or from chemical action. The first of these opinions was 

 mainly supported by the fact that, when two dissimilar metals are made to 



