404 Miscellaneous Intelligence. 



afterwards the boracic acid or borates will wash out and 

 leave the paper as at first. 



Borax itself at first reddens turmeric paper because of the 

 excess of alkali, but as the colouring matter becomes altered 

 by the presence of the boracic acid, the tint becomes of a dirty 

 bluish colour, and then the paper is changed by acids or al- 

 kalies, just as if it had been altered by boracic acid. 



Hence it is probable that the neutral borates have the same 

 power as the boracic acid, of altering the colouring matter of 

 turmeric, for it is not probable there should be an actual se- 

 paration of the elements of the salts by it, especially as they 

 both wash out from it and leave it unaltered. 



Hence also both acid and alkaline borates redden turmeric. 



M. Desfosses, proposes this effect of boracic acid as a 

 test for its presence ; for a very small quantity of it mixed with 

 other acid has the power of reddening turmeric paper in conse- 

 quence of these changes. 



M. F. 



III. Natural History. 



Geology, Medicine, &c. 



1 . Further Retnarks on the Resemblance between certain Varieties 

 of Granite and of Trap. — J. Mac Culloch. 



In a former number of this Journal (Vol. X. p. 29.), I gave a 

 detailed account of some interesting facts occurring in Aber- 

 deenshire, respecting the resemblance of certain portions of the 

 granite of that country to some of the members of the trap 

 family. It was there shown, that, in this district, specimens 

 could be procured from the fundamental granite, and connected 

 with the most common varieties by transition, resembling many 

 of the latest greenstones, and even the basalt of most recent 

 origin which is superincumbent on the latest stratified rocks. 

 The series of specimens formed from these places, is not to be 

 distinguished from a common series of basalt and greenstone ; 

 but the interesting conclusions to which this fact gives rise, re- 

 specting the similarity of origin in these two families, so far 

 removed in position, need not be repeated, as they were suf- 

 ficiently pointed out in the paper to which I have alluded. 



As the instances which I there quoted may, however, seem to 

 require confirmation, particularly to those geologists who are 

 unwilling to abandon the notions in which they have been 

 educated, it will not be useless to point out another set of 

 similar facts, equally open to investigation, and equally con- 



