406 Intelligence and Miscellaneous Articles. 



NOTE ON COLONEL SABINE's PERIODIC AND NON-PERIODIC TEM- 

 PERATURE VARIATIONS AT TORONTO (PHIL. TRANS. 1853). 

 BY S. M. DRACH, ESQ., F.R.A.S. 



To the Editors of the Philosophical Magazine and Journal, 

 Gentlembn, 

 In page 152, the Annual formula is convertible to 

 f,=44°-23-21°-81 sin (a+81° 27'=a')--l°-06 cos (2a-hl61° 32' 

 = 2a'-l°22')~'80cos(3a + 257°42'=3a' + 13°21') 

 + •22 cos (4a + 307° 27'=4o'-18° 2I')--88sin(5a+50°-41 

 =:5a' + 3°-26)-h-325cos6a=44°23'-21°-81sina'-l-06cos2a' 

 — • 80 cos 3a' +• 22 cos 4a' - • 88 sin 5a' nearly, 



at 30° a month, 81° 27'= 2 months and 21 days; which, counted 

 backwards from January 15, brings us to the third week in October, 

 the epoch of mean annual temperature. 



Would therefore the meteorological year from October year n to 

 September year n -)- 1 inclusive produce more approximative results ? 



Oct. 13, 1856. S. M. Drach. 



ON A ZEOLITIC MINERAL (ALLIED TO STILBITE) FROM THE ISLE 

 OF SKYE, SCOTLAND. BY J. W. MALLET, PH.D. 



The specimen to which the following description refers has been 

 in my possession for several years, and has attached to it a lable 

 bearing the name *' Hypostilbite;" but analysis shows it to be a 

 mineral quite distinct from Beudant's hypostilbite of the Faroe 

 Islands, and differing also from both stilbite proper and epistilbite. 



It occurs as a mass of minute crystals, resembling white loaf- 

 sugar, breaking easily, and crushing under the fingers into a coarsish 

 crystalline powder. The separate grains, viewed under the micro- 

 scope, appear as single prismatic crystals, or little groups of three or 

 four, nearly transparent, colourless, and with a pearly lustre, especially 

 on two opposite faces, — closely resembling stilbite in fact in general 

 appearance. 



The crystalline form could not be satisfactorily made out, but 

 seemed to be monoclinic. Hardness a little greater than that of 

 calcite. Specific gravity =2*252. 



Strong muriatic acid poured over the pulverized mineral at night 

 had the next morning formed a distinct jelly. 



On analysis the following results were obtained : — 



Atoms. 



Silica 53-95 1-191—3 



Alumina 20-13 -392—1 



Lime 12-86 -459-1-17 



Magnesia trace 



Potash (with a little soda). . -87 



Water 1242 1-380—3-52 



100-23 



