the working part of the establishment Mr. G. then
took me there, and introduced me to that gentleman,
with whom I passed the remainder of the afternoon,
receiving a full explanation of his new process,
which is this:—a solution of hydrate
of barytes is made in boiling water—the
saccharine solution to be treated is heated to
the same degree, and the two mixed together in
the proportions of 46 parts of hydrate of barytes
to every 100 parts of sugar contained in the solution,
which has previously been ascertained by polariscopic
examination. A saccharate of barytes is immediately
formed in the shape of a copious precipitate;
this, after being thoroughly washed and thus freed
from all soluble impurities, is transferred into large,
deep vats, and a stream of carbonic acid gas forced
into it, which decomposes the saccharate of barytes,
forming carbonate of barytes, and liberating the
sugar in the shape of a perfectly pure solution of
sugar in water, of the density of 20 to 23 degrees
Baume; the carbonate of barytes being thoroughly
washed is again converted into caustic barytes
by burning, so that there is little loss in the operation.
The whole process is certainly very beautiful, and
its economic working has been tried for a year,
on a sufficiently large scale to leave no doubt
as to the economy of the process in refining molasses,
which is the only purpose it has yet been applied to.
The Messrs. Grar were so thoroughly satisfied with it, that when I was there they had taken down their original apparatus, and were re-erecting it on such a scale as to work up all the molasses by it, equal to almost five tons of sugar daily. Owing to this circumstance, I had not an opportunity of seeing the process on a working scale, but was shown the whole proceedings in the laboratory.
The only difficulties I see in applying this process at once to the cane juice, are the large quantity of barytes required, the expense of re-burning it and the entire change in works that would be necessary before it could be introduced. The advantage would be, the obtaining the whole sugar contained in the juice, free from all impurities, consequently white, and in the shape of a syrup marking 20 to 23 degrees instead of 8 or 10 degrees, thus saving fully half the evaporation now required. The sugar made in this way, I was told, contains no trace of barytes.
To show you the degree of economy practised in such establishments in France, I may mention that the washings of the saccharate of barytes are sold to the makers of potash and soda, who make a profit by boiling them down to obtain what salts they contain.
The carbonic acid is obtained by the combustion of charcoal in a closed iron furnace into which air is forced by an air pump, requiring, I believe, about one horse power. From the top of the furnace a pipe leads into a washing vessel, from which the gas is led into the bottom of the


