1876.] Infusorial Earth and its Uses . 349 
plastic mass, called zeiodelite; but no uses have yet been 
made of it. 
By far the most important application of infusorial earth 
in this direction, however, has been successfully accomplished 
by Mr. Frederick Ransome, of England, in the production 
on the large scale of an artificial stone for general purposes, 
to which he has given the name of apoenite. The so-called 
“ Ransome stone,” invented by this gentleman, is made by 
thoroughly incorporating sand and silicate of soda in a 
mixing mill, moulding into the form required of the block, 
and then saturating the same with a solution of chloride of 
calcium, either by exhausting the air with air-pumps, or by 
forcing the solution through the moulded mass by gravita- 
tion or otherwise. The result is the formation of an insolu- 
ble silicate of lime, which firmly cements the particles of 
which the mass is composed, and of chloride of sodium or 
common salt, which is subsequently removed by the free 
application of water. The process of washing to remove 
all traces of the salt from the Ransome stone, which is 
necessary to prevent its efflorescence and secure its proper 
cementation, was found to be in many cases so tedious, 
expensive, and objectionable that the inventor, after many 
experiments, devised the following process, in which the 
use of chloride of calcium is avoided. Mr. Ransome mixes 
suitable quantities of lime (or substances containing lime) 
and soluble silica (i.e., infusorial earth) with sand, and a 
solution of silicate of soda or potassa, which, when inti- 
mately incorporated, are moulded as before, and allowed to 
harden gradually, as the silicate of lime, produced by the 
aCtion of the lime on the silicate of soda, is formed. As 
rapidly as the soda (or potash) of the water-glass solution is 
set free, it dissolves some of the infusorial silica, and again 
gives it up to the lime to form more cement, aCting thus as 
the carrier of silica to the lime, until eventually all the lime 
is combined. In the course of the successive changes that 
take place, a portion of the free alkali appears to be bound 
at each step, with the lime as a compound silicate ; and as 
the result of these several changes the whole of the alkali 
is gradually fixed, thus leaving nothing to be washed out. 
The mass gradually becomes thoroughly indurated, and in a 
very short time is converted into a very compact stone — ■ 
apoenite — capable of withstanding enormous pressure, and 
increasing in strength and hardness with age. 
In combination with magnesite (carbonate of magnesia), 
infusorial earth forms what is described as an excellent 
