316 J. M. Ordway on Nitrates of Tron. 
northern hemisphere, there should be a constant eastward tendency of 
the magnetic declination, such as is indicated by the secular variation 
of the needle. 
c. Axis 45° from magnetic meridian. 
25. When the disc is in or near the meridian, there is aslight 
tendency in the extremity of the needle which is under the 
Opening of the disc, to follow the direction of the top of the 
ring. In all other positions the needle declines from the axis. 
d. Axis variously inclined. 
26. If the inclination of the axis to the meridian is less, or 
| greater, than 45°, the results approximate respectively to those 
obtained when the axis is in the meridian, and when it is in the ce 
equator. hk 
ecgonanienasatianatily 
Art. XXXIII.—Nitrates of Iron; by Joun M. OnpWaAY. 
Or the scattered accounts to be met with respecting the 
action of nitric acid j 
;_et encore le premier ne se forme-t-il quen 
4 5°, et le second, qu’en employant de I’acide 
Si lacide étoit plus concentrée, une portion 
| precipiteroit, et l’on n’en retrouveroit plus 
trés peu s'il avoit 86° 4 40°.” And some 
considerable quantity mingled with 
oe ' Annales de 
 * The 1-16 n 
