62 Botanical Society of Edinburgh. 



observed in palaeontology, the value of the application of Natural 

 History to Geological science mainly depends.] 



C. The genus, in whatever degree of extension we use the term, 

 so long as we apply it to an assemblage of species intimately related 

 to each other in common and important features of organization, 

 appears distinctly to exhibit the phaenomenon of centralization in 

 both time and space, though with a difference, since it would seem 

 that each genus has a unique centre or area of development in time, 

 but in geographical space may present more centres than one. 



a. An individual is a positive reality. 



b. A species is a relative reality. 



c. A genus is an abstraction — an idea — but an idea impressed on 

 nature, and not arbitrarily dependent on man's conceptions. 



a. An individual is one. 



j3. A species consists o^ many resulting from one. 



y. A genus consists of more or fewer of these manies resulting from 

 one linked together not by a relationship of descent but by an affinity 

 dependent on a divine idea. 



And, lastly, 



a. An individual cannot manifest itself in two places at once ; it 

 has no extension in space ; its relations are entirely with time, but 

 the possible duration of its existence is regulated by the law of its 

 inherent vitality. 



b. A species has correspondent and exactly analogous relations with 

 time and space, — the duration of its existence as well as its geogra- 

 phical extension are entirely regulated by physical conditions. 



c. A genus has dissimilar or only partially comparable relations 

 with time and space, and occupies areas in both having only partial 

 relations to physical conditions. 



The investigation of these distinctions and relations forms the subject 

 of a great chapter in the Philosophy of Natural History. That 

 Philosophy contemplates the laws that regulate the manifestation of 

 life exhibited in organized nature, and their dependence upon and 

 connection with the inorganic world and its phsenomena. None 

 teaches more emphatically the difficulties with which man's mind 

 must contend when attempting to comprehend the wisdom embodied 

 in the universe, and none holds out a more cheering prospect of future 

 discovery in fresh and unexpected fields of delightful research. 



BOTANICAL SOCIETY OF EDINBURGH. 



Thursday, 8th April, 1852. — Dr. Seller, President, in the Chair. 



Dr. Murchison exhibited some curious specimens of Extract of Tea, 

 prepared in the form of lozenges by the Chinese. These lozenges 

 were of various forms, and had impressed upon them mottos in 

 Chinese characters, and the figures of different insects, musical in- 

 struments, and other objects. They had been brought from Pekia 

 in the year 1812, and were stated to be used by the Chinese when 



