208 Dr. Mac Culloch on the 



which seems to show that the heat of a climate is not its most 

 essential part, as the upward range of the thermometer in this 

 island is very narrow compared to England ; seldom or never 

 equalling it, at the extreme, by ten degrees. The term mildness 

 is sufficiently unmeaning as a solution of the difficulty ; and I 

 know of no advantage to be derived from indefinite language. 

 One fact however does deserve notice, and that is, the soil; which 

 is, for want of more definite terms, a yellow loam, deep, and pro- 

 duced by the decomposition of gneiss. This is perhaps one of the 

 most extensively advantageous soils for the cultivation of flowers ; 

 while it is certain that many gardeners are still in error on this 

 subject, in preferring dark agricultural soils for that purpose. 

 But I must pass on, lest I should trespass on my narrow limits ; 

 yet not without an example or two of this singular vigour and 

 beauty in thf common flowering plants and shrubs. 



This is very remarkable in the Verbena triphylla, among others, 

 assuming the size of a small tree; and not less so in the Hydrangea, 

 which grows to an enormous bush, and is covered with flowers 

 during a very long season. It will convey a more accurate idea of 

 this vigour, to say that there were cut, in one case, from one 

 plant, at the same time, a thousand and fifty- four flowers, and 

 each of them of a very large size. In general also the flowers are 

 blue, and of an intensity and splendour of colour which never 

 occurs in England ; while among the other mysteries which attend 

 the production of this particular colour in this strange plant, it is 

 observed that those which produce pink flowers on the low 

 grounds, or near the sea, are invariably blue in the higher lands, 

 although the soil is the same. That the sweet, as well as the 

 bitter orange, are annually covered with large crops of ripe fruit 

 out of doors, are proofs that this mysterious mildness, whatever it 

 is, is of more importance than a very hot or a very sunny climate. 



Yet it is worth remarking here, that vigour of growth or splen- 

 dour of colour are circumstances depending on different causes 

 from that vigour of action in other respects, which it requires 

 a hotter, and perhaps also a more luminous climate, to bring forth : 

 and the fact, as relating to vegetable physiology, may perhaps 



