1C>0 Intelligence and Miscellaneous Articles. 



the author assumes that it may be safely said to be in the highest 

 degree improbable, if, as he believes to be the case, we can show the 

 latter to be not contradictory to known physical laws. 



The author then reviews the meteoric theory of solar heat, and 

 shows that, in the form in which it was advocated by Helmholz*, it 

 is adequate, and it is the only theory consistent with natural laws 

 which is adequate to account for the present condition of the sun, 

 and for radiation continued at a very slowly decreasing- rate during 

 many millions of years past and future. But neither this nor any other 

 natural theory can account for solar radiation continuing at anything 

 like the present rate for many hundred millions of years. The paper 

 concludes as follows : — "It seems therefore, on the whole, most pro- 

 bable that the sun has not illuminated the earth for 100,000,000 years, 

 and almost certain that he has not done so for 500,000,000 years. 

 As for the future, we may sajr with equal certainty that inhabitants 

 of the earth cannot continue to enjoy the light and heat essential to 

 their life for many million years longer, unless new sources, now 

 unknown to us, are prepared in the great storehouse of Creation." 



DESCRIPTION OF A NEW MINERAL FROM THE URAL. 

 BY M. RODOSZKOVSKI. 



In 1857 I discovered at Nijni-Jagurt a variety of concretionary 

 silicate of zinc, the existence of which, as far as I am aware, was 

 not previously known in the Ural Mountains. 



It is in concretionary crusts. The surface is covered with small 

 roughnesses, which, seen under a lens, present the appearance of 

 tolerably lustrous indistinct crystals, which are analogous to zeolite. 

 The colour of these is a light blue, with a tinge of green. 



The hardness is 5, the specific gravity 2"707. It is soluble with- 

 out effervescence in acids, gives off water when calcined ; it is in- 

 fusible before the blowpipe, but becomes opake when submitted to 

 the action of the flame ; it dissolves in borax, forming- an insoluble 

 glass. 



The composition of this silicate of zinc, from my analyses, is — 



Oxvgen. 



Silica 26-0 13'507 3 



Oxide of calcium 1-55 0'43 \ 



Oxide of zinc 6G'9 13*133 J 



Water 4'7 4-177 1 



Oxide of copper 1 , 



r, . • t c ■ > traces 



rrotoxide or iron J 



and is represented by the formula 



3ZnSi+Aq. 

 1 This variety of silicate of zinc greatly resembles a variety of con- 

 cretionary carbonate of zinc which I saw at London in the British 

 Museum under the name Smithsonite ; but as its composition, its 

 form, and its colour differ from those of ordinary silicate of zinc, I 

 name it Wagite in honour of M. Waga, the venerable naturalist of 

 Warsaw. — Comptes Rendus, December 9, 18G1. 



* Popular Lecture delivered at Konigsberg on the occasion of the Kant 

 commemoration, February 1854. 



