34 ° 
Infusorial Earth and its Uses. 
[July, 
powder, at Drakeville, has reached £50,000 a month. 
There are different grades of dynamite, but some of it con- 
tains 25 per cent of infusorial earth.” 
An analysis of an average dried sample of the Drakeville 
deposit yielded the writer 47*12 per cent of soluble silica. 
Concerning the application of this curious substance in 
the useful arts quite a chapter might be written. During 
the past few years it has attracted the special attention of 
practical men, and so many and various have been the uses 
for which it has been suggested that their bare enumeration 
may well excite surprise. At least one very important in- 
dustry of recent origin has been practically created by it, 
and its employment in others is steadily growing in extent 
and importance. A summary of the subject in its technical 
aspects, with brief comments upon the more important 
items, is given in what follows. 
The most popularly known and perhaps the earliest appli- 
cation of the diatomaceous earth is its utilisation as a 
polishing agent for stone and metals. For this purpose, 
when carefully freed from grit and other impurities, its con- 
siderable hardness and its wonderfully fine state of division 
fit it most admirably. It may be applied wet or dry. It is 
well known in this connection under the name of tripoli, so 
called from the locality whence it was originally brought. 
Under the name of “ eleCtro-silicon,” “ magic-brilliant,” 
md other trade designations, the diatomaceous earth from 
Nevada and other localities has been extensively introduced 
as a polish for gold, silver, and plated ware, for which — as 
for tin, Britannia ware, and other metals used in the house- 
hold — its wide popularity is the best proof of its excellence. 
