84 



of equal weights of candidum and nigrum (which is called 

 Argentarium) ; of 2 parts of nigrum and 1 of candidum, 

 (called Tertiarium); with this last lead pipes are soldered.* 

 Fraudulent dealers add to the Tertiarium equal parts of album, 

 call it argentarium^ and with it plate or line other metals. 



He gives the prices of these compounds and those of pure 

 album and nigrum, the former 20, the latter 7 Denarii for 

 100 lbs. 



Plumbum album, he says, is rather of an arid nature; the 

 nigrum is entirely humid; " therefore the white is of no use unless 

 it be mixed with another metal. Silver cannot be leaded (lined) 

 with it, it will be melted first." " It is affirmed that if there be 

 too little nigrum mixed with the album, the silver will be 

 corroded by it. Album is melted into brasswork (inlaid, an 

 invention of Gaul), so that it can hardly be known from silver 

 — these works are called Incoctilia" (silvered). He then 

 speaks of the application of this invention to the trappings of 

 horses, and carriages, and other curious productions of Alesia 

 and the Bituriges, a subject which our esteemed Kenrick has 

 lately handled with his usual felicity.f One of Pliny's sentences 

 is remarkable as narrating a class experiment fit for a chemical 

 school : Plumbi albi experimentum in charta est, ut liquefac- 

 tum pondere videatur, non calore, rupisse. 



The meaning seems to be, that the metal is fluid at so 

 moderate a heat as when fused to break by its weight, not 

 burn by its heat the charta on which it is poured. Tin melts 

 at 440°— 442°; Lead at 612°. 



What follows is a very important passage : India neque ses 

 neque plumbum habet, geramisque suis ac margaritis hoc 

 permutat. 



May we be justified by this sentence in refusing to credit the 

 supposition that Tin (plumbum album) was brought overland or 

 by other routes from the Asiatic Isles and shores towards West- 

 ern Europe ? If so, Cornwall chiefly, if not wholly, supplied 

 the Tin which entered so many ways into the comforts and 



* Hoc fistula solidantur. This is the solder of our tinmeu. 

 + See in this Volume p. 52. 



