92 Mr H. M. Stoker on the China-stone and 



employment ; to the shipping, from the quantity annually 

 exported ; but also to the traveller, from the picturesque 

 scenes, the preparation of these articles has added to the 

 previously existing and unexampled ones offered him for con- 

 templation in the various modes of raising and rendering 

 available the mineral wealth for which we have been so long 

 and so justly famed ; and not only to these, but to the prac- 

 tical chemist as well, does it afford matter for speculation, 

 inasmuch as the supply of the former of these articles is so 

 limited, as to require, in the course of a very few years, 

 some cheap and easily available substitute ; whether to be 

 supplied from this or from some other county, is a questio 

 to be determined only by the conjoined efforts of the miner, 

 the geologist, and the analytical chemist. 



From these few remarks, any apology for the appearance 

 of the present essay would only be out of place, especially 

 when we take into consideration the paucity of information 

 possessed even by such men as the jurors of the Exhibition 

 of the past year, as proved by their indifference both to the 

 purity and quantity of the raw material ; and this i3 now the 

 more to be deplored from the contrast presented to us in the 

 degree of attention paid by those jurors who investigated the 

 merits of this article in its manufactured state, and by the 

 observations necessarily made on other raw material, not 

 less than from the fact that in no work with which I am at 

 present acquainted has the preparation or the source of this 

 article been fully described. 



These observations will be found to refer generally to 

 those districts whence the greater amount is attainable, and 

 from them I have reason to hope that some few general laws 

 may be deduced, whereby, when the present source is ex- 

 hausted, other localities may be found in the county for their 

 supply. 



Attention was first directed to the fact, that the disinte- 

 grated granite and clays of our county, as well as those of 

 Devon, when fused or burned, could be rendered available 

 to the potter, in 1768, by the late Mr Cookworthy of Ply- 

 mouth, who extensively exported them to the potteries of 

 Staffordshire for that purpose from Devon ; subsequently to 



