396 Meeting of the American Association 
entirely insoluble in pure hydrochloric acid, when oxygen is absent. _ 
j This which has been made the foundation of an analytical process, 
first recommended by Fuchs, and since by Fresenius, was proved to be 
inaccurate. By a particular apparatus, in which carbonic acid gas in 
one case, and hydrogen gas in another, was made to flow into the : 
he above the liquid and metal, so as effectually to exclude the at- & : 
m re, it was found that continued boiling caused the copper to be 
dissolved ; in marked quantity. Even when exposed to the acid at or- 
dinary temperatures, the atmosphere being entirely excluded, it was 
found ho after a prolonged time the metal: underwent partial solution, 
bubb! ydrogen were evolved, and the dichlorid of copper’ was 
formed. The Professors peers regard these results as — proving 
the ineompetency < of Fuchs’s method, to ances accurate results 
stoppi 
ever either of these is sufficiently simple for difect discussion, the nu 
r and nature of. the real roots of the giver snes can ‘be ee es 
ascertained. Professor Peirce illustrated this method by geometrical 
a and applied it to some very rr cases of algebraic q 
equa 
ars C. WALKER bores ar pe to the Ph sical ee through 
nds of Neptune for the 
ambridge, nffand After nt 5 to the ephemeris a correction 
published by, Mr, W. in the American Journal of Science, the differences 
between the computed and observed: places of Neptune are as follows: 
»  .Obs.—Eph. 
R.A Decl 
0-06 —0°-83 
eo eOB1 —0: 
+0: 78 +1: 86 
—0: 39 +1 25 
—2! 55. +0: 07 
; a1 86. 5 
Mean, —O0- 26 +0: 34 
This comparison shows that no correction is needed as yet, either to 
Mr. Walker’s elements of Neptune’s orbit, or to the perturbations of 
the planet as computed by Prof. Peirce. q 
“ ee pic qa of as &c., at Meteoric Waters, and on the | 
action of the Mineral Acids upon 
Rocers and Prof. R. E. Rog eldspar, §c. By Prof. W. B. 
n abstract of part of peg A may be found in the last volume 
i Journal, page 401. 
rime ay. were also cited disproving the opines which appears 
received among chemists, that the feldspars, hornblendes, &c., 
