a a 
ee ee ee ee 
Porcelain and Porcelain Clay. 4 
agatized, and veins of chalcedony occasionally pervade the 
fissures: they are not impressible by steel, and give fire with it. 
According to the information of Mr. Perit, they are scattere:1 
over the surface of the Island of Antigua, with a profusion 
hardly less than that which Horneman observed of the same 
mineral during his travels over the eastern part of the great Af- 
rican desert. 
It is much to be wished that our numerous intelligent navi- 
gators and travelling merchants would, in imitation of this and 
of a similar example, mentioned below, bestow some share of 
their attention on the natural productions of the countries 
which they visit. In this way they might, on their return, 
render very essential services to the science of their own 
country. 
Arr. VII. Porcelain and Porcelain Clays: 
Titoven the kind offices of a friend, we have been fur- 
nished, from one of the great porcelain manufactories in the 
vicinity of Paris, with a series of specimens, to illustrate the 
beautiful art of fabricating porcelain. The specimens begin 
with the raw materials, and exhibit them in all their principal 
Stages of advancement, up to the perfect vessel, including the 
materials for the glazing, and the colours for the painting, and 
the application of both. At the request of the manufacturer, 
through whose liberality we were indulged with so interesting 
@ gratification, we transmitted to Paris various specimens of 
American porcelain clays. This gentleman has caused them 
to be subjected to trials in the porcelain furnaces, and he finds 
that some of them are equal to the French porcelain clays, and 
some are superior. As our specimens were all labelled with 
the names of the places, in this country, from which they were 
obtained, we hope soon to learn where to look for porcelain 
clays, equal or superior to those celebrated ones from which 
the Superb French porcelain is manufactured. 
Vou... No. 1, 8 
