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 vats by pipes.

At Valenciennes I met with Mr. Cail, who, beside being an engineer
and machine-maker, is interested in sugar-making, both in France and
in the West Indies, and most thoroughly understands the subject. He
invited me to accompany him to Douai, to see a new set of works
which had been set agoing this month. I was of course too glad to
accept his invitation, and started with him at six next morning,
reached Douai at eight, and then proceeded to the works, which are a
few miles out of town. In this work a new process is also employed;
it is that of Mr. Rouseau, and is said to answer well. The beet root
juice, as soon as possible after expression, is thrown up by a
montjus into copper clarifiers with double bottoms, heated by steam
at a pressure of five atmospheres. To every hundred litres of juice
(=22 gals.) two kilogrammes of lime are added (about four and a half
pounds English weight). The lime is most carefully prepared and
mixed with large quantities of hot water till it forms a milk
perfectly free from lumps. The steam is turned off, and the juice
heated to 90 deg. A complete defecation has taken place, the steam
is shut off, and the juice left a short time, to allow the heavier
impurities to subside. It is then run off in the usual manner,
undergoes a slight filtration through a cotton cloth placed over a
layer of about four inches thick of animal charcoal, and runs into a
second set of copper vessels placed on a lower level than the
clarifiers; these vessels are heated by means of a coil of stea