258 Correspondence of J. Nicklés. 
As a general rule I have been very pes and regular in 
taking the observations and have neglected to record but few 
each month, excepting those on the be [ think therefore, if 
the results are erroneous, it is rather owing to a defect of the in- 
struments than to a want of faithfulness in using them. In re- 
gard to the barometer, I have sometimes suspected it was injured 
in the transportation from America, but my doubts were in a 
measure removed by finding that it agreed with the Aneroid Ba- 
rometer of Chevalier Khanikoff and that the measurements of the 
height of Oroomiah above the ocean are nearly like those of pre- 
vious observers. The barometrical records are carefully corrected 
for wget, being reduced to the foregoing point ; but, as I 
did not know the bore of the tube, I could not make the correc- 
tion for enpiIRaciay The diameter of the bore must however 
vary from ith to 3th of an inch. All the instruments have been 
in a favorable position and about ten feet from the ground. 
In one respect, at least, my labor is quite incomplete. As the 
tables now stand, some general notion may of course be formed 
of the tension of vapor, by noting the difference of the ther- 
mometer and hygrometer. But, as the barometrical pressure is 
always to be taken into account, and the pressure at this altitude 
above the ocean is much less than in the United States, a general 
inspection of the tables might lead the reader to very erroneous 
conclusions as to the dryness of this climate. I should have re- 
uced these observations, if I had had the means of doing so 
conveniently. I leave this for those who may be interested in 
the resu aus 
Art. XXVI.—Correspondence of M. Jerome Nickles, dated Paris, 
June 29, 1855, 
Aluminium and Sodium.—Aluminium has already been a 
into the industrial arts. In the session before the last of the Academy 
of Sciences, M. Dumas exhibited in behalf of M. Deville, large eas 
of the chlorid of aluminium, and of the metals sodium and aluminium, 
three hundred kilogrammes of chlorid of aluminium had been already 
made, showing that it may become a material of manufacture on the 
large scale. 
os has been proved that sodium, while superior in energy to potas- 
sium, may be prepared by Deville’s process, with no difficulties not 
sercideriel to the manufacture of the latter metal.. Numerous trials 
have also shown that it may be ve in fusion in contact with the air 
without inflaming, and that it may be run out of the apparatus which 
furnishes it, A metal like sodium, brought within the reach of science 
and the arts, must soon come into extensive 
