Every one finally paid homage to the illustrious inventor, and a committee appointed in the name of the minister affirmed that "the advantageous results given by the experiments of Citizen Lebon have met and even exceeded the hopes of the friends of the sciences and arts." Napoleon I. soon granted Lebon a concession in the forest of Rouvray for the organization of an industry of wood distillation and gas making. Unfortunately, Lebon was obliged to undertake too many things at once. He prepared the gas, and produced acetic acid and tar that he had to send to Harve for the use of the navy. Despite all his trouble and fatigue, he had something like a ray of hope. He believed that he saw the day of fortune dawning. His works were visited by numerous scientists, and among others the Russian princes Galitzin and Dolgorouki, who, in the name of their government, proposed to the inventor to transfer his plant to Russia, he to be free to set forth the conditions. Lebon refused this splendid offer, and, in an outburst of patriotism, answered that his discovery belonged to his country, and that no other nation should before his own have the benefit of his labors.
The hopes of Lebon were of short duration. Enemies and competitors caused him a thousand troubles, and the elements themselves seemed to turn against him. During a hurricane, the humble house in which he dwelt was destroyed, and a fire shortly afterward consumed a portion of his works. Fatality, like the genius of old, seemed to be following up the unfortunate inventor; but sorrows and reverses could not have any hold on this invincible spirit, who was so well seconded by a wife of lofty character. Lebon, always at work, was seemingly about to triumph over all obstacles, and the hour of the realization of his project of lighting on a large scale was near, when a death as tragic as it was mysterious snatched him from his labors. On the very day of the crowning of the emperor, December 2, 1804, the body of Philip Lebon was found lying inert and lifeless in the Champs Elysees, exhibiting thirteen deep wounds made by a dagger.—La Nature.
A NEW PROCESS FOR THE DISTILLATION AND CONCENTRATION OF CHEMICAL LIQUIDS.
ESPECIALLY ADAPTED TO THE MANUFACTURE OF SULPHATE OF AMMONIA. INVENTOR, ALEX. ANGUS CROLL.[1].
By George Anderson, of London.
The paper I have to lay before you describes the last product of the brain of one of your past presidents—Alexander Angus Croll—in connection with our industry. It may not be so well known to some of the younger as it is to many of the older members of the Institute that the fertile brain of Mr. Croll has done much for the improvement and the extension of the gas industry. I consider that he has been the most successful pioneer both in the cheapening and the purification of gas—two elements without which our industry would progress but slowly if at all; and the success which has crowned his efforts, to our advantage, has reflected itself favorably on himself, showing by his financial success that he has also been a good man of business. All these are conditions which enhance the value of this paper. In the present instance, I claim no other credit than that of being the mouthpiece of Mr. Croll, whose assistant I was for ten of the busiest and most important years of his eventful life; and having (with my son Bruce) taken part in the experiments, I have been asked to describe the process to the Institute.
The manufacture of sulphate of ammonia, as hitherto conducted, has consisted either in bringing together sulphuric acid and ammoniacal liquor or in distilling the liquor by external heat, or by the introduction of steam, and bringing it into contact with the acid in the form of gases and vapor of water. In either case a large volume of noxious gases is given off, the chief of which, being sulphureted hydrogen, has to be fixed by another method, in order to comply with acts of Parliament for the prevention of nuisances.
By the processes hitherto used, we sometimes get only 1¼ tons of salts to every ton of acid used; while in the more perfect forms of apparatus, we may get 1-1/3 tons of salts. By Mr. Croll's process, however, we get an increased yield of salts on the acid used, as follows: The experiments were made with sulphuric acid of the specific gravity of 1838, or nearly concentrated oil of vitriol; and the quantity used was 8 ounces in each experiment. The ammoniacal liquor was of uniform strength throughout all the experiments, being kept in a corked jar; and the solution of sulphate of ammonia was passed through filter paper before being crystallized. Thus we obtained a white salt. In each experiment the solution of sulphate was divided into four equal parts by weight, and one part filtered and crystallized to dryness over a spirit lamp; the weight in each experiment being as nearly as possible the same, or 3¼ oz. of salt to 2 oz. of acid—being in the proportion of 26 oz. of sulphate to 1 lb. of acid, or 32½ cwt. of salts to 20 cwt. of acid.
The results surprised me; and being uniform over a number of experiments, pleased me. Still, I preserved the character of a critic and said: "I should like to treat 8 oz. of acid in the ordinary way—saturating it with ammoniacal liquor, and then crystallizing it." "Oh!" Mr. Croll said, "we know what that will produce." I replied: "Yes; but I would like to do it with the precise acid and liquor we have been using, so that we may have the experiment on all fours with yours, barring your process." These experiments were made at his country residence. I was staying there for the night. So next morning I got down before him, went at my experiment, saturated 8 oz. of acid (and a nice smell I made) out in the grounds, treated it afterward by division into four parts, filtered and crystallized it, all as before, with the result that I obtained 2¾ oz., as against his 3½ oz.—or in the proportion of 27½ cwt. of salt to the ton of acid, as against his 32½ cwt.