REV. J. C. ATKINSON ON THE MINERALS OP BERWICKSHIRE. 136 



to which I drew your notice, would be rewarded with very inter- 

 esting results. 



And what have we here ? By the dripping it would seem that 

 the waters of a small spring are escaping ; and you see the dirty 

 white track they have left upon the rock. Up above, at the 

 point where it issues, observe the beautiful golden and deep green 

 moss intermixed. Look a little more closely, and you perceive a 

 pai-t of that moss is almost, as it were, in a state of transition, 

 from a vegetable into a stone. Some of it has, as yet, only a very 

 fine coating, and another part just retains the form of moss ; while 

 the deeper you penetrate in your examination, the more solid does 

 the substance become ; and how tough and hard it is, you find on 

 essaying to break it. There are many springs of this kind on the 

 Whitadder banks ; and large quantities of this calcareous tufa, 

 or ** petrifaction," are in continual process of deposition by the 

 evaporation of their waters. When first removed from the influ- 

 ence of the water, the tufa is very soft, but soon hardens. I have 

 little doubt that, at some of the springs, casts might be taken from 

 moulds, as at the Baths of San Filippo in Italy, though, of course, 

 greatly inferior. This tufa, which in some places is almost compact 

 enough to be called travertin, is by far the most plentiful variety 

 of carbonate of lime. Calcareous spar is rare. One variety I met 

 with near Hutton Bridge, was composed of a number of very small 

 crystals, and had very much the appearance and structure of the 

 horehound candy which form one of the numerous class of 

 ** sweeties." Rarely, too, may a variety be foimd, which, for want 

 of another name, I shall call Botryoidal Calc-spar. These varie- 

 ties are seldom pure enough to give the peculiar cleavage of calca- 

 reous spar ; and the same remark may be made of a kind of stala(v 

 titic carbonate of lime, which has been deposited in the crevices of 

 some of the sandstone rocks. 



Here is a specimen, which at first greatly perplexed me. I only 

 find it in one place, on the Foulden side, about 300 yards below 

 Hutton Bridge. It looks not unlike a piece of burnt bone as it 

 lies ; is very heavy ; is somewhat fibrous in its structure ; and has 

 a sort of silky lustre, which is not seen in the cross fracture. It 

 more nearly resembles carbonate of lead in appearance than any 

 other of the common minerals. Mr Tennant tells me it is celestine, 

 or sulphate of strontian ; and since I asked his opinion I have 



