Miscellanies. 175 



feet Fraunhofer, with a yellow screen glass, having a slight tint of 

 green. He saw them distinctly in the 3| feet Dollond, with a red 

 screen glass, used by Prof. Henry, for some four minutes after the 

 rupture of the ring, though none was visible in the Fraunhofer tele- 

 scope ; at least none is recollected to have been seen, though he ex- 

 amined the sun in the direction in which the ring broke. The testi- 

 mony of so experienced an observer, who, in examining this arch and 

 brush of light, used, interchangeably, the yellow and red screen 

 glasses, in favor of their far greater visibility through the red screen 

 glass, appears to be conclusive on the subject. This remarkable cir- 

 cumstance, not hitherto noticed in European observations, and first 

 suggested by Robert Treat Paine, Esq., from his observations at 

 Washington, appears to be now confirmed. It is one of great im- 

 portance ; as it seems to furnish evidence of the existence of a lunar 

 atmosphere, through which, as through our own, the red rays have the 

 greatest penetrative power. It also leads to new views concerning the 

 cause of the remarkable appearances of the beads of light, and the dark 

 lines frequently noticed ; since it shows that their appearance may be 

 completely modified by a change in the color, and, consequently, in 

 the absorbing power of the screen glass through which they are ob- 

 served. 



The fact, noticed by most of the observers, that before the forma- 

 tion and after the breaking of the ring, the edge of the moon off the 

 sun was distinctly visible, and illuminated for some distance within the 

 moon's surface, is just such as would be presented by a twilight caused 

 by a lunar atmosphere ; nor does there seem to be any other plausible 

 explanation of this phenomenon. 



Mr. Lea submitted the following description of a new shell, recent- 

 ly taken in the vicinity of Cincinnati by Mr. T. G. Lea. 



MELANIA CINCINNATIENSIS. 



" Testi valde depress^., inferne compressa, fused, trifasciatS., bicarinatd, apice 

 acuminatci ; aiifractibus quaternis ; aperturcL subrotundd." 



This is a very minute species, and very remarkable for its roof-shaped spire, and 

 two carinas which are colored. 



On motion of Dr. Patterson, the Committee appointed on the late 

 eclipse, were instructed to make and collect observations in relation to 

 the occultation of stars in the constellation of the Pleiades, which will 

 occur on the 27lh instant. 



January 4, 1839. — Dr. Dunglison made a verbal communication 

 on the subject of the vaccine virus and its alledged liability to lose 

 its protective character under certain circumstances. 



He stated that, in consequence of severe epidemic small-pox having 

 recently occurred in England, from which many who had been pre- 



