202 



_ w (m ~ t) 



~ M {t'— m) ' 



and another where the water is the hotter body, 



yf (t — m) 



u {m — t')^ 



the mean of which is the specific heat of the alloy pretty 

 exactly. The result gave the specific heat of the normal 

 alloy = .0879, water as unity, and that of the anomalous 

 alloy = .0848 ; both of which are below the specific heat as- 

 signed by Dalton to brass. 



The normal alloy is malleable, flexible, ductile, and la- 

 minable. In the anomalous alloy there is an absolute negation 

 of all these properties. 



The normal alloy readily amalgamates with mercury, at 

 common temperatures ; the anomalous alloy will not amalga- 

 mate with mercury even at 400° Fahr. 



When the anomalous alloy is heated to incipient redness 

 in a glass tube, a minute trace of water, and of a burned or- 

 ganic substance, probably adherent oil, are discoverable; it 

 suffers no change, however, but a slight increase of density. 

 The normal alloy suffers no change when so treated. The 

 normal alloy, treated on charcoal with the blow-pipe, fuses 

 at once into a bead. On treating the anomalous alloy so, 

 the fragment swells rapidly to more than twice its original 

 bulk, on becoming bright red hot ; it then glows, or becomes 

 spontaneously incandescent, in the way that hydrated oxide 

 of chrome and some others do, and instanlly contracts to less 

 than its original bulk, and becomes a fluid bead, which, on 

 coohng, differs in no respect from the original alloy. 



The anomalous alloy, when pulverized in an agate mor- 

 tar, forms a black powder, devoid of all appearance of a 

 metal; its filings also are quite black; while those of the 

 normal alloy, produced by the same file, possess the usual 

 metallic lustre. These facts, in connexion with the black 



