carefully; and from year to year, better, simpler, and cheaper methods of making it were discovered. With every improvement in the mode of manufacture, its price fell, and its sale increased in an equal ratio.

"Sulphuric acid is now manufactured in leaden chambers, of such magnitude, that they would contain the whole of an ordinary sized house. As regards the process and the apparatus, this manufacture has reached its acme-scarcely is either susceptible of improvement. The leaden plates of which the chambers are constructed, requiring to be joined together with lead (since tin or solder would be acted on by the acid), this process was, until lately, as expensive as the plates themselves; but now, by means of the oxy-hydrogen blowpipe, the plates are cemented together at their edges by mere fusion, without the intervention of any kind of solder, and so easily, that a child might perform the operation."

Up to this point, then, we find that Le Blanc's little discovery, the promised reward for which never was paid to him, has created sulphuric acid into an important article of commerce, and opened a new field for capital and industry.

"Again," Liebig goes on, "saltpetre being indispensable in making sulphuric acid, the commercial value of that salt had formerly an important influence upon the price of the acid. It is true that one hundred pounds of saltpetre only are required to one thousand pounds of sulphur; but its cost was four times greater than an equal weight of the latter." All this has likewise been changed. Thanks to some other of those men with ready eyes and active brain from whom the world receives so much, to whom it hitherto has given back so little.

"Travellers had observed, near the small seaport of Yquique, in the district of Atacama, in Peru, an efflorescence covering the ground over extensive districts. This

Com

was found to consist principally of nitrate of soda. merce, which with its polypus arms embraces the whole earth, and every where discovers new sources of profit for industry, took advantage of this discovery. The quantity of this valuable salt proved to be inexhaustible, as it exists in beds extending over more than two hundred square miles. It was brought to England at less than half the freight of the East India saltpetre (nitrate of potassa); and, as in the chemical manufacture, neither the potash nor the soda was required, but only the nitric acid, in combination with the alkali, the soda-saltpetre of South America supplanted the potash-saltpetre of the East in an incredibly short time. The manufacture of sulphuric acid received a new impulse; its price was much diminished, without injury to the manufacturer; and, with the exception of fluctuations, caused by the impediments thrown in the way of the export of sulphur from Sicily, it soon became reduced to a minimum, and remained stationary."

Thus, therefore, the little discovery of M. Le Blanc, assisted by the quiet observation of a traveller, has caused the blessing of an active commerce to descend upon Peru. Furthermore, heroes of battles, if any of you be economists, give ear to this:-"Potash-saltpetre is now only employed in the manufacture of gunpowder; it is no longer in demand for other purposes; and thus, if Government effect a saving of many hundred thousand pounds annually in gunpowder, this economy must be attributed to the increased manufacture of sulphuric acid," originated by that discovery for which, by a soldier-loving Government, Le Blanc was bilked of his reward.

"We may form some idea of the amount of sulphuric acid consumed, when we find that five thousand hundredweights are made by a small manufactory, and from twenty

thousand hundred-weights to sixty thousand hundredweights by a large one, annually. This manufacture causes immense sums to flow yearly into Sicily. It has introduced industry and wealth into the arid and desolate districts of Atacama. It has enabled Russia to extract platinum from its ores, at a moderate and yet remunerating price." Note here another article of more extended commerce, to which the little discovery of the manufacture of soda out of common salt is in a direct line grandfather. Platinum was demanded because the vats employed for the concentration of sulphuric acid are constructed of that metal; they cost one or two thousand pounds apiece. What more do we owe to M. Le Blanc's little fact? "It leads to fre

quent improvements in the manufacture of glass, which continually becomes cheaper and more beautiful, being now made chiefly from soda, and not from potashes. It enables us to return to our fields all their potash-a most valuable and important manure in the form of ashes, by substituting soda in the manufacture of glass and soap."

We have not yet done with the summary of consequences flowing from the single fact disclosed by M. Le Blanc. We would observe, however, that this is no isolated instance. There is no fact in the whole range of all the sciences, a correct knowledge of which has not been turned, or cannot be turned, to the advantage of the human race. Science points the way to commerce, and the path of commerce is the path to peace to the perfecting, so far as perfection can be looked for, of the human family. Commerce must awaken our sleepers, before Christianity can pour its voice into their ears. Missionaries before merchants are in most parts of the world—the seed before the plough. The men who direct that plough-who point the path of commerce, and discover new tracks of our human

industry to travel in-humble explorers-patient men, who spend their lives in bringing up out of the mines of ignorance into the upper light a few small grains of truth, so precious, yet apparently so trivial; these do their large share of the real work of the world, howsoever rarely we may read of them in the Calendar of the world's distinctions and titles.

We are wandering, however, from M. Le Blanc's discovery, and must not do that yet, because there still remains a consequence resulting from it, which it would not do for an Englishman to omit. Liebig says, “I have already told you, that in the manufacture of soda from culinary salt, it is first converted into sulphate of soda. In this first part of the process, the action of sulphuric acid produces fuming concentrated muriatic acid, to the extent of one and a half time, or twice the amount of the sulphuric acid employed. At first, the profit upon the soda was so great, that no one took the trouble to collect the muriatic acid,—indeed, it had no commercial value. A profitable application of it was, however, soon discovered: it is a compound of chlorine; and this substance may be obtained from it purer and more cheaply than from any other source. The bleaching power of chlorine has long been known; but it was only employed upon a large scale after it was obtained from this residuary muriatic acid; and it was found that in combination with lime it could be transported to distances without inconvenience. Thenceforth it was used for bleaching cotton; and, but for this new bleaching process, it would scarcely have been possible for the cotton manufacture of Great Britain to have attained its present enormous extent,-it could not have competed in price with that of France and Germany." That is on account of the high price of land in England, and the

large quantity that would have been required for bleachingground.

"In the old process of bleaching, every piece had to be exposed to the air and light during several weeks in the summer, and kept continually moist by manual labour. For this purpose, meadow land, eligibly situated, was essential. Now, a single establishment near Glasgow, of only moderate extent, bleaches fourteen hundred pieces of cotton daily." Fancy the acreage of land that would be requisite to produce in the old way a decidedly inferior result.

Then, again, the cheap muriatic acid got in this manner is applied to the extraction from old bones of their glue. Furthermore, the extended applications of sulphuric acid have led to its economic use in the processes of refining. A one twelve-hundredth or one two-thousandth part of gold formerly not worth extracting, and left wasted in the silver, is extracted now, and pays the refiner for his work. He returns to his employer, without charge, the silver and the copper separated from each other, paying himself with the modicum of gold-one to one-and-a-half per cent. of the value of the silver, which sulphuric acid has enabled him without difficulty to extract.

We must interrupt here our catalogue of consequences which have followed from the process pointed out by M. Le Blanc; we break it off abruptly for want of space, and not for want of matter. The space already occupied we certainly do not regret; for it is worth while now and then to consider in detail what we all acknowledge in the gross. The services of scientific men are very important; we are all ready to say that; but we are not all ready to see how absolute and solid are the gains which we derive from silent meditation in a student's chamber. The sense of service, the consciousness of working for the world, is too often