The Scottish Naturalist. 



157 



shape of glassy felspar and silicious sinter. I may, however, add 

 in a sentence that quartz crystals have been formed artificially in a 

 very dilute solution of soluble glass (silica dissolved in caustic 

 soda) left exposed to the air for 8 years, groups of four-sided 

 pyramidal crystals, perfectly transparent, hard and unaffected by 

 acids, being produced. 



Further, solutions of silica in carbonated water, or in very dilute 

 hydrochloric acid, under high pressure, exposed to a temperature 

 of 200 0 to 300 0 F., have produced microscopic crystals, (Bischof, 

 II, pp. 472-3). These instances may appear unimportant in 

 connexion with the subject of the origin of sand ; but they point- 

 to processes of nature, which possibly one day may be discovered, 

 and may reveal what is, at present, a close secret in nature, the 

 origin or formation of granite, with its several component elements. 



Sands are not, however, all silicious. There are calcareous 

 sands, composed mainly of particles of carbonate of lime. That 

 of the Bermuda Islands may be taken as typical of this description. 

 It is of coral formation, and so abundant that the inhabitants have 

 the greatest difficulty in preserving cultivated ground shrubs and 

 houses from being covered by it. The sand of the Island of 

 Ascension is also calcareous, being principally composed of shell 

 fragments. The shell-sand of Malta, rich in colour, consisting of 

 red coral and minute shells, may be included in calcareous 

 sands. Besides these, there is volcanic sand, like that of Teneriffe, 

 largely composed of particles of iron, and auriferous sand, of which 

 that found in Northern Bengal is representative. 



THE ANTIQUITIES OF DAVAN AND KIOOKD. 



By Alexander Hogg, Alford. 

 HE District of Kinnord, or, we would rather say, the 



X ancient district of Davan, of which Kinnord forms only a 

 part, is situated on Deeside, about 35 miles west from Aberdeen, 

 and is a vale about seven miles in circumference. History, as 

 we shall see, gives only the slightest clue to the position and 

 extent of this "town;" but even its rather obscure reference, 

 along with the signification of the ancient Celtic names which 

 have been handed down, together with existing remains, enable 



