Chemistry. ; 259 
ysis. The water is first seen on the pertion of the tube between the 
contractions ; it is dissipated by gently heating it; this part of the tube 
is then allowed to cool, and the mercury soon makes its appearance, 
condensing in its turn without any difficulty. At the end of the opera- 
3 tion, the part of the tube containing the mercury is separated by slightly 
_-‘Moistening the heated tube; the portion of the tube is weighed with 
the mercury it contains, the mercury poured out, the particles adhering 
as toit removed by nitric acid; it is then washed, dried, and weighed 
-_—s again. ~The difference of the two weights gives the weight of the 
4 8..A New Method of estimating Copper ; by M. PeLovze, (Comptes 
“| Rendus, Feb., 1846.)—It is based upon the discoloring of a solution of 
if @ persalt of copper in ammonia by any deoxydizing agent. The fol- 
ie lowing is the method of procedure. One gramme of pure ‘copper is 
x dissolved in half an ounce of nitric acid, the solution diluted with a lit- 
tle water, and slight excess of ammonia added. A solution of sulphu- 
‘Tet of sodium in water is next made, (Pelouze used about 4 oz. toa 
‘quart of water—this however is altogether arbitrary,) poured into a 
- graduated. tube, and let fall drop by drop upon the solution of copper, 
/ heated to boiling, until the discoloration is complete. The quantity of 
Sulphuret used is noted, and it then becomes a standard solution, of 
Which so many divisions of the graduated tube are required to discolor 
‘one gramme of copper. 
If we now wish to analyze an alloy of copper, it is dissolved in ni- 
tric. or Nitro-muriatic’ acid, super-saturated. with ammonia, heated to 
boiling, and discolored by the solution of sulphuret ; the required quan- 
uty of which is noted, and from our knowledge of the amount requi- 
Ted for one gramme of copper, we estimate the quantity of ‘this metal 
Present. 
“Se By this method M. Pelouze says that we can approximate to within 
one-half per cent., and even less if great care be observed. ‘The pres- 
‘ ence of tin, zinc, lead, arsenic and antimony, do not interfere with the 
Aecuracy of the result; nickel and cobalt will. The solution of -sul- 
Phuret slowly undergoes alteration: by contact with the atmosphere, so 
(eis necessary prior to each assay, to test the strength of the sul- 
‘i ‘ Phuret by a known weight of copper. eta: . fe i 3 J. L. 8S. 
A new test for Manganese; by R.. Parturs, (Chemist, April, 
__ 4846.)—Place the solution of manganese in a bottle, so that it may 
Cover the bottom of the phial to the depth of about the tenth of an 
— Inch, and lay on the fluid a common stick of phosphorus, by which 
Means one half of the stick will be exposed to the air; the mouth of - 
: ‘the bottle: should be but imperfectly closed. After keeping the bottle 
_ Inthe dark fora few hours, the fluid will be found to possess a beauti- 
