1868. | Ransome’s Patent Concrete Stone. 161 
successful, he succeeded in obtaining a vast amount of excessively 
useful information regarding the properties of those several material 
in their varied conditions. 
Notwithstanding his repeated failures, Mr. Ransome took out a 
patent for a process of making artificial stone, being confident that 
in the six months, at the end of which he would have to file a com- 
plete specification, he would be able to discover some means of at- 
taining his desired object. 
The next experiments were with the use of pulverized glass 
which he mixed with the sand. ‘The mixture was first subjected 
to hydraulic pressure in iron moulds, and then by the application of 
heat the glass was fused and the particles were consequently mixed 
together. This plan, however, also failed, owing to the stone either 
breaking or running into vitrified masses when subjected to the high 
temperature of the kiln. The idea of obtaining liquid glass and 
mixing it with the sand next occurred to his mind, and this was 
within three weeks of the time when the final specification had to 
be lodged at the Patent Office. 
Mr. Ransome’s attention having been drawn to the solution 
called silicate of soda, determined to make further experiments, 
with a view of testing its applicability to furnish the sort of cement 
he so much desired. “Flint, although apparently a most inert 
substance, is, in its chemical constitution, as much an acid as 
sulphuric acid is. In the one case we have one atom of silica 
combined with three atoms of oxygen, and the other, also, one 
atom of the base—sulphur—combmed with the same number of 
atoms of oxygen. Using the ordinary chemical symbols, flint is, 
$1-0*; sulphuric acid, 8O*. Now it is found that just as sulphuric 
acid combines with potash or soda to form a salt, so does silicic 
acid combine with either of these alkalies. The difference between 
the reactions is, that in the case of sulphuric acid, the affinity for 
the alkalies is more energetic, and the union takes place more ra- 
pidly and at a lower temperature. There are two methods of 
combining potash or soda with flint. The first, called the dry 
process, is to take a quantity of fine sand, which is nearly pure silex, 
and to mix it in a crucible with an excess of the alkali, and then 
to bring the whole mass to a high temperature, when a combina- 
tion readily takes place. If the quantity of alkali used is just 
sufficient to saturate the silicic acid—-that is, if there is only one 
particle of the alkali to one particle of the acid, as represented in 
the formula K O, $10%, the glass so formed is less soluble in water 
than when there is an excess of alkali, as in the formula *K O, Si O%. 
This process is necessarily an expensive one, for two reasons—the 
large quantity of alkali which is required, and the high tempera- 
ture rendered necessary to effect the combination. 
“The other, or moist process, although not liable to the last 
