durability that it may be preserved with the greatest ease, and sent to distant countries, it seems as if a new means of subsistence was actually offered to us. Take the Argentine republic, take Australia, and consider what they do with their meat there in time of drought, when they cannot get rid of it while it is fresh. They may boil it down, and mix the essence with flour, (and we know they have the finest in the world,) and so prepare a substance that can be preserved for times when food is not so plentiful, or sent to countries where it is always more difficult to procure food. Is not this a very great gain?

IX.

THE WORLD'S EXPOSITION OF 1851.

Presuming that an examination of, and a report on, the works of industry and art to be exhibited at the World's Fair would be advantageous to the agricultural and manufacturing interests of the Union, the following communication on the subject was addressed to the Secretary of the Interior:

PATENT OFFICE, February 10, 1851.

SIR: The present year will be one of unprecedented interest as regards the arts and industry of the world. The natural productions, the plastic arts, and the results of the inventive ingenuity of all nations-their machinery and manufactures-will be displayed side by side, their respective merits scrutinized, and prizes, it is announced, awarded by discriminating and impartial judges.

The United States have been invited to participate in the great concourse of material sources and productive skill, and, judging from the arrangements already made, they are likely to be largely represented in every department.

A report of such an exhibition of the skill, industry, and ingenuity of the world would be of the highest value to this Office, even if viewed. only in relation to the various branches of invention of which it is the primary function of the Office to take cognizance. In discharging the daily duties of examining and deciding upon inventions, many questions arise which can only be decided by extensive researches among books, or in workshops and factories. The works pertaining to the arts contained in the Library of the Patent Office are too few in number to give all the information required, and, even if much more numerous, they would not serve to make known all the inventions that have been patented in foreign countries, of which many are not published till the patents expire, and others only in abstracts or imperfect descriptions.

Hundreds of minor devices and processes, simple and seemingly trifling accessories of staple mechanism, will be found there, of which it is equally important for this Office to be informed. These constitute a class of contrivances not found in books, and a knowledge of them is therefore highly desirable. Instances have occurred where patents have been issued for such, because evidence of their use in work-shops was lacking. They often present remarkable examples of simplicity and efficiency, and of neat turns of mechanical thought, which few besides practical men can appreciate. Of course none but the eye of one familiar with the details of modern manufactures and arts could detect them.

The usefulness of such a report, however, would not be confined to the immediate operations and duties of this Office. If prepared with due

regard to the state of the arts in this country, and to the ground which we have yet to occupy, it would, by becoming a work of reference among farmers, mechanics, manufacturers, artists, and inventors, react favorably on the future transactions of the Office-often relieving it from the necessity (always disagreeable) of refusing in cases lacking the essential features of novelty. Inventors would be apprized of many facts necessary to be understood before applying for patents; and, while deriving useful hints from the inventions of foreign nations, they would probably be spared the mortification of finding too late that they had, in some important points, been anticipated, and thereby avoid the waste of much time, ingenuity, and money.

From the nature and extent of the proposed exhibition, it is believed that much of the inventive talent of the world will be presented in its most recent developments. The direct utility of the information which may be there collected, and which is not elsewhere attainable, will, it is thought, be sufficiently important to warrant the expense of collecting it, for the purpose of embodying it in the Annual Report of this Bureau. Accompanied by necessary illustrations, the documents would be of lasting interest.

Under the impression that the Commissioner of Patents has no authority to depute any person or persons for the purpose of making such a report at the expense of the Patent Fund, I beg to call your attention to the subject, and solicit for it your consideration. The reporter should, of course, be a person thoroughly conversant with mechanical science and the entire range of the arts, and it would be well were he attended by an assistant and draughtsman.

I have the honor to be, very respectfully, your obedient servant, THOS. EWBANK.

Hon. ALEX'R H. H. STUART,

Secretary of the Interior.

One of the clerks of this Office, who had been sent out in charge of the articles shipped in the St. Lawrence, was authorized by the Department of the Interior to remain and report on the contents of the Crystal Palace with special reference to such substantial arts and inventions as should be found more immediately adapted to the United States-to the development of our resources and to the genius and condition of our people.

As no report has been made by him, the undersigned solicited of the Executive Committee for the United States the one made to that committee by Mr. Riddle, the American Commissioner. It was politely furnished, and, with the accompanying letter, is here presented.

WASHINGTON, January 27, 1852.

SIR: By order of the Executive Committee on the London Industrial Exhibition, the following resolution, which was adopted at a meeting of said committee, held on the 20th instant, is hereby transmitted to you:

"On motion, Resolved, That the chairman and secretary of the Executive Committee communicate to the Commissioner of Patents, in

compliance with his request, the report of Mr. Edward Riddle on the Industrial Exhibition, for publication as a portion of the Patent Office Report."

In compliance with the above, the report is here with transmitted.
Very respectfully, your obedient servant,

JNO. C. G. KENNEDY,

Secretary.

PETER FORCE, Chairman.

Hon. THOMAS EWBANK,

Commissioner of Patents, Washington.

REPORT ON THE WORLD'S EXPOSITION

BY EDWARD Riddle.

PART I-CHEMICAL AND PHARMACEUTICAL PRODUCTS.

In this class of the department appropriated to Great Britain for the display of raw materials was found little that was interesting, or much that was inquired into, by the majority of those who daily visited the building; but to others to those who had a higher aim in view than a mere cursory glance at objects of unseeming interest to the scientific and practical chemist-in fact to all who sought to acquire knowledge rather than amusements-there was presented an ample field for inquiry, and a large scope for gathering valuable information."

Chemistry was known to the ancients only as the art of "making silver and gold," or what is more generally known by the name of alchemy. Various definitions of its modern meaning have been given— that by Dr. Black being most generally received, namely, that "Chemistry is the study of the effects of heat and mixture, with a view of discovering their general and subordinate laws, and of improving the useful arts."

From the earliest times to the seventh century the operations in chemistry were limited to expressions, digestions, and decoctions, and it may be naturally inferred that at this period the dawn only of chemistry had begun, and that it was rather a collection of unconnected and ill-founded axioms, the result of observation, than a science established upon the broad basis of an infinite variety of experiments.

From the seventh to the seventeenth century several important facts were discovered, and several products added to the few already known; the chief of these discoveries being the process of making sulphuric acid from green vitriol, or sulphate of iron, of nitric acid from nitre, and hydrochloric acid from common salt. Several salts and some alkaline bodies were also discovered, or more perfectly known.

Of the earths in general, but little was known, and even that little was unsupported by the principles of chemistry. Clay was distinguished from sand, but not by its genuine chemical characters.

About the year 1674 Sir Isaac Newton contributed some new and general ideas on chemical phenomena to the Royal Society. He observes:

that sugar dissolves in water, alkalies unite with acids, metals dissolve in acids; and he inquires whether these effects are not occasioned by an attraction between their particles? Copper dissolved in aquafortis is thrown down by iron. Is not this, he inquires, because the particles of the iron have a stronger attraction for the particles of the acid than those of copper, and do not different bodies attract each other with different

degrees of force?

From the seventeenth to the commencement of the present century little further advancement was made in this science; but from that period. to the present time chemistry has received a marked impulse from the unremitting attention of the most eminent men of nearly all nations; discoveries have been made, inventions brought out, and systems promulgated, which would have astonished the world had they occurred at an earlier period; and this, too, not only as applied to the purposes of medicine, manufacture, &c., but also, and that to a very great extent, as connected with agriculture.

In a commercial point of view, chemistry has also made some very rapid strides. Within the last twenty years the manufacture of caustic and carbonate of soda has originated and developed itself to a degree almost unparalleled in the history of commerce. The fires of the kelp business on the coasts of the islands of Scotland are scarcely now extinct, when vast factories, employing large numbers of individuals, produce, in enormous quantities, the same alkali which, until recently, was derived from the fused ashes of marine plants. The manufacture of this alkali, by an ingenious decomposition of common salt, by the simple aid of sulphuric acid, chalk, saw-dust, and coal, is now prosecuted to a vast extent for the supply of the industrial arts generally, the quantity used in medicine being comparatively insignificant. At some alkali works, fifty and sixty tons, and upwards, of common salt are decomposed every week, and converted into caustic and carbonate of soda. The alum factories are not less extensive; at these establishments crystallizations, on a scale emulating those of nature, are constantly in progress. The manufacture, also, of sulphuric acid, and of the compounds used by the dyer and calico printer, occupies a prominent feature of commercial enterprise.

The prussiates of potash, forming large masses of yellow and red crystals, and the green but perishable crystals of copperas, are substances largely used in the arts, and the colors and dyes produced by their assistance present themselves in every direction when textile printed fabrics. are examined.

Amongst the varied specimens of chemical and pharmaceutical products displayed, were many worthy of notice, and, taken throughout, they formed a valuable collection, and furnish remarkable illustrations of the extensive applications of chemistry to modern arts and manufactures.

Crystal of Copperas, or Sulphate of Iron.-T. Bramwell & Co., Newcastle-upon-Tyne.

This substance, so largely used in the arts for dyeing, &c., and also in chemistry and pharmacy, is obtained, as a natural product, from aluminous chalybeate springs, as well as by the spontaneous decomposition of certain native sulphurets of iron, or iron pyrites; and is prepared in