383 
The analyses of felspars from the North of Ireland, quoted 
by Dr. Apjohn, could not, Sir Robert Kane remarked, have 
any reference to a question as to the nature of the felspars in 
the south-east, nor could the crystallographic or analytical de- 
tails into which Dr. Apjohn had entered. The real question 
was, the average constitution on the great scale of the granitic 
district lying to the south of Dublin, and on this Sir Robert 
Kane considered the conclusions suggested in his former no- 
tice to be perfectly unimpeached, although in special localities 
deposits of true potash felspars (orthoses) may occur, a fact of 
which Sir Robert Kane was, of course, perfectly aware, and 
never could have contemplated to deny. 
The Rev. Dr. Lloyd read a paper on the magnetic influence 
of the moon. 
‘¢ The influence of the moon upon the position and move- 
ments of the magnetic needle seems to have been first recog- 
nised by Professor Kreil. From the discussion of the mag- 
netical observations made at the Prague Observatory, in 1839 
and 1840, he has inferred that there existed a small periodical 
variation in the position of the freely suspended horizontal 
magnet, dependent upon the position of the moon with respect 
to the meridian. The question has been again examined, in 
this and in other bearings, by Mr. Broun, the able Director 
of Sir Thomas Brisbane’s Observatory at Makerstoun, in Scot- 
land, and the action of the moon has been apparently traced 
in a variety of periodical laws, dependent not only upon her 
hour-angle, but also upon her declination and distance from 
the earth. 
** Notwithstanding the very remarkable nature of the phe- 
nomenon thus announced, the question has since remained 
unexamined, and the conclusions unconfirmed, by other ob- 
servers. Whether the small changes deduced by Professor 
Kreil and Mr. Broun were thought to be within the limits of 
the errors of observation, or the apparent improbability of 
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