SUOAR. 201 



man from whom I did not receive the greatest politeness, I started for Valen- 

 ciennes. My first essay was upon the latter personage, who evidently with a 

 considerable grudge showed me a simple room in his works where four centri- 

 fugal machines were at work raised the cry of ruin, if the French improve- 

 ments were introduced in the West Indies, and informed me he had nothing else 

 worth seeing. I returned to Valenciennes, thinking if this is the way I was to 

 be treated, I might as well have stayed at home. That this was a solitary in- 

 stance of illiberality, you will presently see. I next called upon Mr- Grar, by 

 whom I was received in a very different manner ; he at once offered to show me 

 over his works, and especially that part of them where a new process, disco- 

 vered by Mr. Dubranfaut, was carried on, every part of which was fully ex- 

 plained. Mr. Dubranfaut's laboratory is connected with these works, and having 

 inspected 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 so- 

 lution 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 pro- 

 portions of 46 parts of hydrate of barytes to every 100 parts of sugar contained 

 in the solution, which has previously been ascertained by polariscopic examina- 

 tion. 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 carbon- 

 ate 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 cer- 

 tainly 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 ro -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 te 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 mark- 

 ing 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 potass 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. Gail, 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 ac- 

 company 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. Ilouseau, and is said to answer 

 well. The beet root juice, as soon as possible after expression, is thrown up by 



