Earthen Vases known by the Name of Etruscan. 55 
pencil. The paintings may be made more perfect, in proportion 
to the degree of heating which the vessel undergoes ; for the 
varnish enters in this manner the sooner into the pores of the clay, 
and loses its fluidity, on which account the delineations are more 
distinct. But the more the vessels are heated, the more quickly 
must the paintings be applied. 
As it is only the outside that requires to be covered with var- 
nish or paintings, vessels may easily be heated for this purpose, 
by filling them with burning charcoal or hot embers. But, if 
vessels, having little depth, are to be painted within, they must 
be previously heated in a proper furnace, or among hot cinders. 
Although the black coating produced in this manner upon 
the surface of earthen vessels, agrees in many of its qualities 
with the varnish of the antique Grecian vases, and it is not im- 
probable, that a similar substance, and a similar mode of paint- 
ing, was used in their manufacture ; yet the varnish prepared in 
the manner above described, differs from the ancient varnish in 
this respect, that it does not resist a very great degree of heat ; 
nor have I as yet succeeded in my efforts to discover, by what 
means the faculty of sustaining the power of an intense heat 
could be given to varnish prepared of asphaltum . However, it 
is evidently not impossible, that time may have done something 
in this respect, which art could not produce. 
It is well known, that asphaltum and naphtha were among the 
substances known to the ancients, and that they were applied 
by them to various purposes. Pliny, in fact, relates, that in- 
scriptions made with Jet (Gagates) upon earthen-ware, are not 
effaced*. But, from what we learn with regard to this Gagates 
of Pliny, it is to be inferred, that it was not the Jet of modern 
times, but asphaltum ; which renders it probable, that the art of 
making a coating for earthen-vessels of that substance was 
known to the ancients. The varnish and paintings, indeed, 
which occur in the sepulchral vases of the Greeks, do not seem 
to have been applied by the Romans to earthen-ware manufac- 
tures ; for no traces of them occur among the numerous remains 
of Roman pottery *f*. A covering, however, in some respects si- 
* Natur. Hist. lib. xxxvi. cap. 34 
f Consult. Broccki , sulle Vernici usate dagli Antichi, Bib!, Ital. t. vi. p. 453. 
463. 
