No. 275.] 
205 
It is impossible to speak at the present time of the quantity which 
those localities will probably furnish. I was able to expose only a small 
portion of the beds which I visited; it would not be safe to make any 
estimate on those partial excavations. There are circumstances, how- 
ever, which are favorable to the general impression which prevails in 
that vicinity, that the substance is abundant. One or two facts in par- 
ticular, go to corroborate this position; for instance, its occurrence in 
numerous places, and which are scattered over an extent of country of 
15 or 20 miles in length. It would be an anomaly, if throughout so 
much territory, there should not be an abundance of this valuable mate- 
rial. 
This variety of clay is produced by the disintegration and decompo- 
sition of jrranite. Those granites, which are of a coarse texture and 
contain large lamina of mica, or are intermixed with scales of talc, are 
the most subject to this change. In the granite of Athol and Johns- 
burgh, there is more or less of pearl white talc, an association which I 
consider an advantage to the clay; its presence will increase the fusibi- 
lity of the silex and alumine, and impart a rich porcellaneous aspect, or 
a greater translucency to the body of the ware; besides it adapts it for 
glazing and forming enamels for the common earthen ware, even if it is 
not employed for the production of the finer varieties of porcelain. In 
fact, it is of great importance that other materials besides salt, lead and 
the metallic oxides should be employed for glazing even the commonest 
articles of pottery, and the discovery of some substance which may be 
used as substitutes for those oxides, which are so readily acted upon by 
the weaker acids in domestic economy, has long been a desideratum. 
It remains, therefore, only to determine the truth of the conjecture, 
that of its abundance, to render it an important addition to the natural 
resources of the State. 
The porcelain clay beds furnish us with some geological facts which 
are worth at least a passing notice. I found that they all contain con- 
cretions of silex, and of the oxides of iron and manganese. 
The silicious nodules belong to the same variety of quartz which is 
usually denominated hornstone, and like this substance, often contains 
cavities lined with crystals of quartz, some of which appear under the 
primary form of the species, a form much sought for and esteemed by 
mineralogists on account of its variety. They are small, and only large 
enough to be seen distinctly by the naked eye* 
The concretions are evidently masses of secondary formation as it re- 
gards the bed in which they occur; and their appearances, together with 
