216 The Scottish Naturalist. 



minerals I can only repeat what my friend, the Rev. W. Peyton 

 said in his Report, namely, that in every case the nature of the rock, 

 gangue, or matrix in which minerals occur should be noted. 

 Finally, I would strongly urge the advisability of each Society 

 becoming possessed of one or more good petrological micro- 

 scopes, so as to encourage the study of the minute characters of 

 minerals and rocks. This is a field of work in which very much 

 remains to be done, and in which young geologists, blessed with 

 good eyes and assiduity, may hope to advance the science and 

 win laurels for themselves. Let me, however, add one word of 

 caution. The microscope is an admirable and, indeed, indispen- 

 sable servant. Do not let it become your master. Never 

 imagine that an adequate knowledge of rocks is to be obtained 

 by the microscopic examination of thin slices only. A mere 

 description of hand-specimens is not enough ; the rock itself 

 must be studied in the field, and viewed in all its relations and 

 aspects : the weathered and altered portions must be scrutinized 

 as carefully as those that are freshest. If this had always 

 been done, we should have been spared much useless and mis- 

 leading nomenclature. We should not then have found three 

 different portions of one and the same rock-mass described as if 

 they were three separate and distinct rock-species. 



I fear, I have detained you too long, and will now bring these 

 somewhat discursive remarks to a close by expressing the hope 

 that this Union may become every year more fruitful in results. 

 May it quicken a generous emulation and strengthen and sustain 

 he spirit of research and love of truth in our midst. 



ON THE BETTEE UTILISATION OF THE SPEATS OP THE 



TAY AND FOETH. 



By F. BUCHANAN WHITE, M.D., F.L.S. 



IT is with considerable hesitation that I venture to bring under 

 your notice the subject of the following note, since it is not 

 in any sense a scientific one, and hence objection may be taken 

 to its discussion at a meeting devoted to natural history. As, 

 however, it deals with the uses to which one of the animals indi- 

 genous in our district may be put, and as the matter is of some 



