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[Assembly 
form the essential materials in all the finer kinds of pottery. They are 
at least the most important elements in the China, French and English 
porcelain; they also enter into the composition of the common Liver- 
pool ware, but in a smaller proportion than in the French or English 
porcelain. 
These substances occur at many localities in the United States, but 
generally they are not sufficiently pure and free from colouring matter, 
to render them objects of value; especially is this the case with fdd- 
spar. It is abundant, but contains frequently too large a proportion of 
the metallic oxides, which in the process of fusion, imparts colour to 
the glazing or enamel, a circumstance which entirely destroys its utility 
and value in this art. 
The localities of porcelain clay which fell under my notice, were in 
Athol and Johnsburgh, in Warren county, and Minerva, in Essex. 
The mode in which it occurs is in layers more or less distinct, or in 
layers interlaminated with those of different colours, as yellow, red and 
brown. At first view, they might be mistaken for ochre beds; still the 
peculiar reds and browns are entirely different from the oxides of iron 
generally termed ochres, and their nature becomes apparent from their 
association with the white variety. 
It is remarkable, that the latter which is in the midst of the coloured 
portions of the bed, should have been deposited without any intermix- 
ture of the oxides so strongly developed in the adjacent portions. 
Its colouring matters, I find, consists of a mi^^ture of the oxides of 
iron and manganese. 
The white variety is soft to the touch, and free from that harsh and 
meagre feel common to some varieties of this species of clay. This 
peculiar soft feel is owing probably to an intermixture of talc which oc- 
curs in it in the form of thin white scales. 
My opinion of the excellent quality of this clay has been confirmed 
by an experienced artist, D. Henderson, Esq. of Jersey City, who has 
been engaged for a number of years in the manufacture of the blue or 
Liverpool ware. It is but just to remark, that at this establishment was 
made the first dining plate in the United States, and that the beauty of 
the articles now manufactured at this establishment is equal to any of 
the imported wares from Liverpool. 
