Hot-houses. — That of Lime. 251 



since many who fancy themselves to be wooing her prosperoii^ly 

 by abstractions, find, when their attentions become more particu- 

 lar, that she has only been coquetting with them. 



While on this tubject, we may also notice the theory of Pro- 

 fessor Parrot of Dorpart, who has written on the freezing of salt 

 water as it respects the origin of the polar ice. Though navi- 

 gators say that the polar ice contains no salt, yet the author thinks 

 and proves that mere tasting cannot decide the problem. If the 

 ice in the polar regions contains no salt, it camiot be frozen sea- 

 water, but ice of glaciers which cover the pole of our earth, and 

 to which our European glaciers are mere molehills. The unsalt 

 water flowing from the glaciers is lighter than the sea-water, and 

 consequently keeps on the surface, makes the latter less salt, and 

 thus more liable to freeze: therefore the ice which covers the po- 

 lar regions must increase and continue to increase every year in 

 height and extent; for this reason the climate of Iceland and 

 Cireenland becomes continually more severe, and these countries 

 lose more and more of the inhabitable surface, &c. 



HOTHOUSES. 



The deformity and unseemly appearance of all the construc- 

 tions that have been resorted to for hothouses, are proved by their 

 being generally banished to a distance from the mansion of the 

 owner, and iiid in the kitchen-garden ; and the attempts hitherto 

 made to remove the defects by stone piers, parapet walls, and 

 other architectural forms, have only tended to defeat the object 

 of the structure by obstructing a portion of the light. — A new 

 system has ju-t l)een offered to horticulturists by Mr. Loudon, 

 who has been long known as a professional rural architect, which 

 seems to promise considerable improvement in this department. 

 He has invented a solid wrought iron sash bar not only applicable 

 to all the purjioses to which wooden frames have been hitherto ap- 

 plied for framing glass; but, being capable of receiving any form 

 by bending, capable of being made into the form of domes and other 

 elegant structures, fitted to ornament, as appendages, the most 

 elegant mansions. He has, as the simplest way of showing their 

 advantages, erected a variety of these structures on his premises 

 at Bayswater. ■ " 



FLU AT OF LIME. 



It is remarked in a late Number of Thomson's Journal, that 

 fluor spar occurs very rarely in Scotland. We are informed that 

 it has been observed by Dr. iMacCulloch, on more occasions than 

 one, in tlie granite of Aberdeenshire, occupying small veins and 

 unaccompanied by any other substance: hi these cases it was al- 

 ways of a purple colour, but not crystallized. The same minera- 



' *^ IM logist 



