[We find the following information communicated to the Literary Gazette, apparently by the parties connected with the improvement.]
Considerable interest has been excited in the market by the introduction of an improved native raw sugar, which portends very great advantages to all who are engaged in this so long unprofitable branch of colonial and commercial intercourse. It is pure raw sugar, obtained direct from the cane-juice, without any secondary process of decoloration or solution, and by which all necessity for any subsequent process of refining is entirely obviated. It is obtained in perfectly pure, transparent, granular crystals, being entirely free from any portion of uncrystallisable sugar or colouring matter, and is prepared by the improved process of effecting the last stages of concentration in vacuum, and at a temperature insufficient to produce any changes in its chemical composition; the mode of operation first proposed by the late Hon. Ed. Charles Howard, and subsequently introduced, with the most important advantages and complete success, into the principal sugar-refineries of Great Britain.
By this improved and scientific process of manufacture, the application of which to the purpose of preparing raw sugar from the cane-juice has now first been proposed, the most singular advantages are secured to the planter, in an increased quantity of sugar, the product of his operation, and in saving from the immense quantity of deteriorated material, uncrystallisable sugar and molasses, which were products of the former mode of operation, from the intense and long-continued degree of heat employed in the processes. The time and labour of the operation are also greatly decreased; the apparatus possesses the power to make double the quantity in the same space of time as the old method, and this is ready for shipment in four days, in lieu of three weaks, as heretofore. The sugar likewise readily commands an advanced price in the market to the planter of ten or twelve shillings per cwt.
This improved sugar readily ensures a preference for all purposes of manufacture, solution, or domestic economy. It is a purer sweet, and of a richer mellifluous taste than even the best refined; it is not apt to become ascescent in solution; and, from its superior quality, it well answers all purposes of the table. In the manufacture of rum from the molasses, which are separated during the first process of the operation, there is no danger of deterioration in the production of empyreuma, and a far purer spirit is obtained than that made from ordinary molasses.
This improved process is now in complete and successful operation on eight estates in Demerara. The general introduction of the process is considered by the best practical judges to ensure certain means of revivifying the spoiled fortunes of the planters, and to open a new era in the prosperity of those portions of the British crown, of which this forms the principal staple commodity of support.
[According to Dr. Moseley, the art of refining sugar, and what is called loaf sugar, is a modern European invention, the discovery of a Venetian, about the end of the fifteenth or beginning of the sixteenth century. Sugar candy is of much earlier date, for in Marin's Storia del Commercio de Veneziani, there is an account of a shipment made at Venice for England in 1319, of 100,000 lbs. of sugar, and 10,000 lbs. of sugar candy. Refined, or loaf sugar is mentioned in a roll of provisions in the reign of Henry VIII.
The process of refining sugar in vacuo is the most useful application of "the fact that liquids are driven off, or made to boil at lower degrees of heat when the atmospheric pressure is lessened or removed."[3] The first part of the process is to dissolve impure sugar in water, and after clarifying the solution, to boil off or evaporate the water again, that the dry crystallized mass may remain. Formerly this evaporation was performed under the atmospheric pressure, and a heat of 218° or 220° was required to make the syrup boil; by which degree of heat, however, a portion of the sugar was discoloured and spoiled, and the whole produce was deteriorated. The valuable thought occurred to Mr. Howard, that the water might be dissipated by boiling the syrup in a vacuum or place from which air was excluded, and therefore at a low temperature. This was done accordingly; and the saving of sugar and the improvement of quality were such as to make the patent right, which secured the emoluments of the process to him and other parties, worth many thousand pounds a-year. The syrup, during this process, is not more heated than it would be in a vessel merely exposed to a summer sun.
Lord Brougham, in his Introduction to the Library of Useful Knowledge, characterizes this as a process, by which more money has been made in a shorter time, and with less risk and trouble, than was ever perhaps gained from an invention; and as "the fruit of a long course of experiments, in the progress of which known philosophical principles were constantly applied, and one or two new principles ascertained."[4]
The scene of this discovery was, in all probability, the Deepdene, near Dorking, the retreat of the late Mr. Thomas Hope, the author of Anastasius. Here the Hon. Mr. Howard, brother of the Duke of Norfolk, resided at the commencement of the last century, and is stated to have enjoyed that philosophical retirement which may be described as the happy haven of a truly great mind. He planted a portion of the grounds, the greater part of the estate being so admirably disposed by nature as almost to forbid the fashioning of men's hands. At Mr. Howard's death, the estate descended to the Duke of Norfolk, who sold the property, in 1791, to the late Sir William Burrell, whose lady wrote the following lines, which are on a tablet in the grounds:
"This votive Tablet is inscribed to the memory of the Honourable Charles Howard, who built an oratory and laboratory on this spot: he died at the Deepdene, 1714.
If worth, if learning, should with fame be crown'd,
If to superior talents, fame be due,
Let Howard's virtues consecrate the ground
Where once the fairest flowers of science grew.
Within this calm retreat, th' illustrious sage
Was wont his grateful orisons to pay,
Here he perused the legendary page,
Here gave to chemistry the feeling day.
Cold to ambition, far from courts remov'd,
Though qualified to fill the statesman's part,
He studied nature in the paths he lov'd,
Peace in his thoughts, and virtue in his heart.
Soft may the breeze sigh through the ivy boughs
That shade this humble record of his worth;
Here may the robin undisturbed repose,
And fragrant flowers adorn the hallow'd earth.--January 1792."
The tablet is of plain wood—black letters painted on a white ground. It is an unostentatious memorial, which has been respected amidst the extensive alteration and embellishment of the grounds by the late Mr. Hope. To our minds, neither of the treasures of art which are assembled within the splendid saloons of the adjoining mansion, or sculpture gallery, will outvie the interest of this humble tribute to the memory of departed genius.]
"This votive Tablet is inscribed to the memory of the Honourable Charles Howard, who built an oratory and laboratory on this spot: he died at the Deepdene, 1714.
If worth, if learning, should with fame be crown'd,
If to superior talents, fame be due,
Let Howard's virtues consecrate the ground
Where once the fairest flowers of science grew.
Within this calm retreat, th' illustrious sage
Was wont his grateful orisons to pay,
Here he perused the legendary page,
Here gave to chemistry the feeling day.
Cold to ambition, far from courts remov'd,
Though qualified to fill the statesman's part,
He studied nature in the paths he lov'd,
Peace in his thoughts, and virtue in his heart.
Soft may the breeze sigh through the ivy boughs
That shade this humble record of his worth;
Here may the robin undisturbed repose,
And fragrant flowers adorn the hallow'd earth.--January 1792."
THE LANDERS VOYAGE AND DISCOVERIES ON THE NIGER.
The travellers, in embarking on the Atlantic, had solved the greatest problem in African, and even in modern geography;—one which had exercised the ingenuity and conjecture of so many learned inquirers, and in the efforts to solve which so many brave and distinguished adventurers had perished. This discovery divested the Niger of that singular and mysterious character, which had been one chief cause of the interest that it had excited—when seen rolling its ample flood from the sea towards vast unknown regions in the interior. The circuit by which it reaches the Atlantic assimilates its character to that of ordinary rivers, without any much more remarkable windings than are found in others of similar length. It displays, however, a magnitude considerably greater than had been suggested by any former observation.