424 Scientific Intelligence. 
objections to the proposition of oF po geh 4 ot only would the method of cold 
milling consume a much greater amount of time and labor; but it would be exceed- 
ingly sete lt, if not impossible ise procure any alloy ¢ e composition of which ed 
ned so nearly constant a the case with yellow-metal.* It is 
probable that a test like the one applic’ to this j alloy could be found anywhere ed 
the w 
ag 1, : = frequently stated in chemical text-books that yellow-metal is always pre 
pared * best-selected” copper, and one is led to infer that a metal of peculiar ah 
ei 
tain a sufficient quantity of copper of uniform character, or indeed of any one kind, 
from which to am are the lange 2 geste ty of sheathing which is us fag an an estab- 
lishment where expense would a secondary consider eae as, for example, in a 
government gt fo it might vit ti pomible t repare an alloy cons netantly ‘from 
the same sorts of copper and of zine, in which cube, although the a mo cit of zine lost 
a rth 
h 
st varied kinds of copper, not only because the supply of the best sah is limited, 
bat particu larly f from the fact, at owing to the coal ss ag which exists between 
the various founderies.—or rather, by force of the laws which re nial et supply and 
eman rine ie are obliged to remelt large quantities of old copper sheathing,+ the 
ye of which is unknown to them, and which may have been originally prepare red 
m copper of inferior quality. 
“Now since many of the Pears of copper are eliminated when it cade Pe 
zine, being a i on the s e of the melted metal as a crust or hie 
fe 
; Oo tw e ase 
kind or nrg of | me the amount of it removed, or, Fahne is the same thing, 
eft to unite with a given weight of zinc,$ must continually 
the ge might ascertain at least “proxi stale the pri of . alloy. 4 
“That of the first iinjortines that every alloy used for sheathing shall possess 
some one sSeptastngs composition, so that it may endure equally w hee on all hore 
the ves ms: and that no Sail action ee occur between the m tal of differe 
siti 
—of kinds 
sr used in its preparation, is a pie piesa ig to ack use. “This 3 is true, and the 
a 
it must always depend upon the c opper metallurgy. It pi 
reibly, for example, to the low brass which Bobierre has proposed to 
aca tes for the ordinary s entree vernek for since the “test” eans of which 
* An alloy of constant syscacatogsin oak however, possibly be prepared, by adding 
known quantities of meite ae ~ determined volumes of molien yellow-metal which 
en prepared by the usual m 
The popular notion, thata canoe ‘more compact <yeinet-incesinen by remelting 
any alloy, may also have sume connection wil jens 
t This explains the remark of Karsten (loc. cit., S 336 "4 that perfectly pure copper ¢ 
e up from 15 to 25 per cer eatin scams mpure, and still afford product uf better 
a aah tenac ious and mo: le 
case, both by alloying with the foreign metal and by 
uniting with any oxygen whic may sori been suerte with the latter. As the work- 
co 
Scere »wever, that.os-e.tule: ile manufacturer of alloys of copper 
iways use the best copper they ean ¢ e itis generally m sre tn 
todoso For the purer mictal je,40-much the greater will: be 1 the total amount 
porlbegiees are. You atay wren as in ether words, the Joss, mentioned 
which would ocenr from elimination of impurities, will be smaller. 
