318 ON THE METEOROLOGY OF IRELAND. 



there can be no doubt of the services which meteorology, properly 

 studied, may be made to contribute to those interests which it is 

 the duty of every Government to promote. The health of man, 

 the operations of agriculture by which he procures his food, and 

 many other of his material interests, are dependent upon climat- 

 ological relations, which must be known and studied before they 

 can be applied. Every one acknowledges the fact, that the salu- 

 brity of a district, and its adaptation (or the reverse) to particular 

 human constitutions, is intimately connected with its meteorological 

 conditions. And the same thing is true of all organized beings, and 

 especially of those which are subservient to the uses of man. Thus, 

 the question of the naturalization of exotic plants is, mainly, a me- 

 teorological problem, dependent upon the climatological relations of 

 the region to which the plant is indigenous, and of that to which 

 it is to be transferred ; and the importance of obtaining accurate 

 data for its solution will be recognised, when it is borne in mind 

 that, in Europe, most of the plants useful to man belong to this 

 class, and that those hitherto acclimatized probably bear a very 

 small proportion to the whole. Lastly, the processes of cultivation, 

 to which these vegetables are to be subjected, are also connected 

 in an intimate manner with meteorological knowledge. We may 

 instance this connexion in the operations of irrigation, and of 

 drainage, both of which are dependent upon the knowledge of 

 the amount of rain-fall in the district to be operated on. 



It is true that meteorological science has been hitherto compa- 

 ratively barren in such applications ; and the fact itself, with many 

 persons, would be accepted as evidence that abstract and practical 

 knowledge are wholly separate and unconnected. But, when pro- 

 perly understood, it leads to a different conclusion. Superficial 

 knowledge in this science can indeed yield but few practical 

 results ; and those by whom such results have been hitherto sought 

 have expected to find them at the surface. There are indeed 

 cases such, for example, as the one last referred to in which 

 the connexion between meteorological science and its applications 

 is obvious and simple, and in which, accordingly, that connexion 

 has been traced and made use of. But in general it is otherwise. 

 In a subject so complex as the laws which govern the aerial enve- 

 lope of the earth, and where so many causes are in operation, prac- 

 tical applications can be obtained only from mature theoretical 

 knowledge. Thus, it may be shown that the knowledge of the 



