RImhatl. 69 



one's called fcECulce, seems to consist in their being hidden be- 

 hind the bright spots or lumps of shining matter I have before 

 mentioned, when going off the western Hmb, and the contrary 

 takes place when entering on the eastern limb, while in the mid- 

 dle of the disc there are rarely, if ever seen, any bright spots or 

 lumps of shining matter, probably from the more intense light 

 of the sun's centre then rendering them invisible. 



It is somewhat curious, that although the author quotes Mr. 

 Adams, upon the variable paths of the spots, he has not disco- 

 vered, in his observations, that these varied paths arise partly 

 from the different inclinatiori of the sun's axis to an azimuth 

 circle, at different hours of the day, on account of the earth's 

 diurnal motion, and partly from the variable inclination of the 

 sun's axis to an azimuth circle, arising from the earth's annual 

 motion : even under the influence of both these causes, the same 

 spot which at sunrise appears to advance from the southern to the 

 northern limb, will, in consequence of the sun's apparent motion, 

 appear to advance from the northern to the southern limb at sun- 

 set: but if we confine ourselves to observations upon the meri- 

 dian, that part of the phaenomena depending upon the earth's 

 annual motion, alone remains, and the spot will travel northivard 

 when the axis inclines eastward, and southward when it in- 

 clines westward. When observed out of the meridian, their 

 path is, in strictness, influenced by both these causes. Their 

 curvilinear direction results from our alternately seeing a little 

 more of the sun's northern, or southern polar regions, when the 

 axis is least inclined, by which means they are convex to the 

 sun's north and south poles by turns, in spring and autumn ; 

 this curvature is, therefore, a couseciuence of the earth's annual 

 motion. The Author's remark, that " these irregularities are 

 of' rare occurrence," is, therefore, the result of a very slender 

 acquaintance with these subjects- A Corrkspondent. 



RHUUARB. 



By a late analysts made by Mr. Brande on the finest Russian 

 rhubarb, it appeared to contain 



Water S-2 



Gum 31-0 



Kesin .. 100 



Extract, tan, and gallic acid ., . . 26'0 



Phosphate of lime 2-D 



Malate of lime ()-5 



Woody fibre 16-3 



lOO-O 

 Journ. of Science, No. 20. 



MAG- 



