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in solution, is poured off, and other water added; and this must be repeated until all taste of the sulphate of potash has disappeared. The mixture is then to be thrown into the clarifier, and intimately mixed with the cane juice when lukewarm; the above quantity being added to every 100 gallons. Line must be used to neutralize the cane-juice when the temperature has reached 150°. The whole must be boiled for a few minutes and filtered as before.

8. Defecation by sulphuric acid. About two fluid ounces of sulphuric acid, diluted in thirty times its bulk of water, is thrown into 300 gallons of cane-juice, at a temperature of 120°, and the whole well stirred together. In about three or four minutes, four ounces of lime, prepared as directed, are to be added, and the stirring continued until the temperature reaches 1700. More lime is then to be added until the liquid is perfectly neutral. It must boil for a few moments, then be filtered.

At the first sight this would appear to be a most unskilful and injurious way of treating cane-juice. The action of the sulphuric acid, if long continued, would convert the whole of the sugar into glucose; and it is not improbable that this effect is produced to a very small extent, even in the short time that the two are in contact. The injury, however, is less than, under the circumstances, might be supposed.

But it is not on healthy cane-juice that this method of defecation should be employed; for the results obtained by the others are, in such cases, very much superior, whilst they are unaccompanied by any mischievous consequences. There are, however, certain states, in which cane-juice is occasionally found eminently benefited by this mode of treatment.

Almost all viscid cane-juice is so, but that which is obtained from one of the conditions of the cane, described, usually, as being" burnt," is the one to which it is most applicable.

9. Defecation by diacetate of lead. When seven parts of finely powdered litharge, six parts of sugar of lead, and thirty parts of water, are digested together at a moderate temperature, the liquid which is found at the top consists of this salt in solution in the water. It constitutes the liquor plumbi subacetatis of the pharmacopoeia, and is often considered as a tribasic salt.

If to 300 gallons of cane-juice, accurately neutralized with lime or chalk, five ounces by weight of this liquid, diluted in a quart of distilled water, be added, and the whole be carefully stirred and heated, the most complete separation of all the organic matters, sugar alone excepted, is immediately effected.

A patent was taken out a few years ago by some parties in this country, for defecating cane-juice and other saccharine liquids by this means. It was therein proposed to precipitate any excess of the diacetate of lead which might remain in solution with the biphosphate of lime.

This process requires a double clarification; the acetate of lead should be added in one vessel, then the cane-juice, having been deprived of all the insoluble coagula which had resulted from the

action of this substance, must be passed into a second; and therein, when mixed with a certain quantity of the biphosphate of lime, it must be boiled for a few minutes, and again filtered.

On the addition of the biphosphate of lime, it is presumed that the soluble diacetate of lead will be converted into the insoluble phosphate of lead, and that the acetic acid will form, with the lime, an acetate of lime.

That this double decomposition would take place under ordinary circumstances, must be admitted; but that it will always do so, at least, perfectly, when sugar is present in the solution, may be doubted.

I have defecated cane-juice repeatedly with the diacetate of lead, employing, however, generally the sulphate of alumina as the decomposing agent. In every instance the test of sulphuretted hydrogen was applied to the filtered liquor; and it not unfrequently happened, that, in spite of all the care bestowed, a quantity of lead was detected in it.

For this reason, from the additional time and labor required for the double clarification, and from the amount of acetic acid set free, which, whether in that state or when combined with a base, would prove injurious to the sugar, I conceive that this process would be inapplicable to the manufacture of sugar in the colonies.

Indeed, it has been used there, and the consequences which ensued to a great number of persons who made use of the sugar, are now a matter of history. The effects produced in the case alluded to, were, no doubt, much more severe than they would have been, had the cane-juice or syrup been properly treated; so that a portion of the lead having been rendered insoluble, had been separated by means of filtration. The fact of their having been produced, however, indicates the impropriety of admitting the employment of the salts of lead in any of the processes, either of the manufacture or the refining of sugar. Its presence is easily detected; and, if no other evil consequence ensued, its discovery would cause all sugars, imported from the estate where it had been employed, to be regarded with suspicion, if not altogether unsaleable, for a long time afterwards.

10. The bark of the wild elm, theobroma guazuma, has been used in Martinique and Guadaloupe for defecating, or rather for clarifying cane-juice, with considerable success it is said. I have never seen this substance employed, and therefore am ignorant of its value as a defecating agent.

I have now mentioned all the methods of defecation, which I think may be employed with advantage in a colonial boiling-house. 1 have endeavored to point out the importance of this operation, and to show, that upon its being well or badly performed depends much of the success of all the subsequent processes.

That defecation may be effectual, a temperature sufficient to produce the ebullition of the cane-juice is necessary. As at present performed, the cane-juice is not allowed to boil; otherwise the separation of the flocculent coagula and other solid matters from the liquor in which they are suspended, would be impracticable. The

heat is raised to that point, merely, which is necessary to produce the cracking of the cane-juice; and this degree effects a partial separation only of the substances which are coagulated by heat.

Should the temperature exceed the above point, ebullition would ensue, and filtration is then required to separate the coagula. The advantages which filtration at this stage of the manufacture present may be stated as follows:-1st. The greater facility of managing the operation, as the cane-juice being allowed to boil, the attention at present required to the due regulation of the temperature may be dispensed with. 2d. Ebullition is essential to the complete coagulation of the albumen. 3d. Economy of time, as, after two or three minutes of smart boiling, the liquor is allowed to run into the filters at once. 4th. An increase in the quantity of liquor, as nearly the whole passes through the filters, the solid matters alone being retained. 5th. The complete separation of all solid matter, and the greater transparency of the defecated juice.

The necessity for the filtration of the cane-juice being performed, either at an early or later stage of the manufacture, is so obvious and so universally admitted; and as it is an operation which can be performed in every boiling-house, as at present constructed, during some part of the process of sugar-making, it is surprising that it has not been universally adopted.

The filters in use in Europe to separate the mechanical impurities. from syrups, are known by the name of bag filters: they consist of a number of strong calico bags, about eighteen inches wide, and from three to five feet in length, each of which is introduced into another bag of the same length, but only six inches wide, and made of a strong and open canvass. Into the neck of each sack thus arranged, is inserted a short metal tube, to which the sack is tied, and by which it is fixed to the bottom of a cistern adapted to receive the cane-juice as it comes from the clarifier. This vessel is placed over the case in which the filters are contained.

It is obvious, by such an arrangement, a large amount of filtering surface is obtained in a very small space. We are, therefore, supplied with a means of most perfect, and, at the same time, most rapid filtration. This apparatus can very easily be made in every colony. The case may be very conveniently constructed of wood, and at the bottom should be attached a cock, which either allows the liquor to escape into the coppers, when practicable, or, when that is not the case, into a receiver constructed for the purpose. The apparatus should be placed under the cock of the clarifier, and, of course, the number of them must be equal to that of the clarifiers. Each Should contain a set of twenty bags; and another set should be provided for use when the first are being cleaned. The accompanying sketch will enable us to form an idea of the construction of a set of bag filters, and their mode of application.

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If the double sieve, formerly described, is not employed for straining the cane-juice previously to its admission into the clarifier, it ought now to be used and placed between the cock of the clarifier and the lower part of the upper cistern of the filters; otherwise the bags would be speedily choked, and the operation would consequently be retarded.

A very few dollars would be required to form the necessary number of filters if expended in the colony. If preferred, they may be obtained from any of the coppersmiths in the large towns of England and Scotland.

In the manufacture of beet-root sugar, the defecated juice, instead of passing through bag filters, is made to percolate through beds of animal charcoal, which has already been nearly exhausted by the filtration of inspissated syrup. On an estate where animal charcoal is used for the filtration of the syrups, it may be advisable to wash out the adhering syrup with cane-juice instead of water, as it may be considered more economical. I doubt, however, whether this would be a very practicable operation on a large estate, and when time is so much an object.*

The foregoing remarks are applicable to the clarifying vessels now in use in the colonies. These vessels, perhaps, might be made a little deeper with advantage.

Steam defecating vessels have been lately constructed. They consist of an iron chest lined with copper, in which is coiled a hollow pipe, made of the latter metal, having an area and length sufficient to supply the due amount of high pressure steam to effect a rapid ebullition of the cane-juice.

Were steam the heating medium in use in the other stages of the manufacture, no doubt it would be equally applicable to the one before us. But to use it in this part of the process where it is not required, and not in the others, would be a piece of folly, which, I trust, it is not necessary to point out.

Perfectly practicable; used on two estates in Louisiana; on plantations greatly preferable to the bag filters, which are very troublesome.-[Note by a friend.

Art. III-INDUSTRY OF THE SOUTHERN AND WESTERN STATES.

VIRGINIA-NORTH-CAROLINA--SOUTH-CAROLINA-GEORGIA-FLORIDA

ALABAMA— LOUISIANA-MISSISSIPPI-TENNESSEE-KENTUCKY

OHIO-MISSOURI-MICHIGAN-ILLINOIS-INDIANA-10WA-WISCON

SIN.

THE Secretary of the Treasury, it will be remembered, in 1845, issued a circular to all the manufacturing, commercial and agricultural interests of the different states of the Union, and appended to his report of that year the various answers which had been received in his office. These answers being partial and very incomplete, were not digested, but published in extenso. The manufacturers, for a large part, did not answer at all; and from many of the states, there came but the most meagre returns.

As, however, among these papers thus published by the treasury, there are many of considerable value, embodying a vast amount of practical information, we have thought some service might be done by an analysis of them, especially of those relating to the Southern and Western States, which are in general most complete.

From many interesting points there are no returns, and often where they are given, many discordances exist in different statements. The parties often appear to have a case to make out, and we are sometimes inclined to suspect the influence of politics. Nevertheless, as we give both sides a hearing, no mischief can

accrue.

Nothing more than such a state of things should urge upon the states the importance of establishing BUREAUS OF STATISTICS, in connection with their governments, as was lately done in Louisiana. The expense would be a mere trifle in any case; the advantages inappreciable. Mr. Burke, in his last Patent Report, says: have been informed, that a bill has been introduced in the legislature of Louisiana, providing for the establishment of a Bureau of Statistics. It is ardently hoped the example will be speedily followed by the other states of the Union."

It will be observed, that these returns were made several years ago, and that agriculture, commerce and manufactures have increased vastly in all the sections since then. In regard to most of the states, the reader will find in the volumes of our Commercial Review, published in 1846, 47, 48, the very latest, most complete, and reliable particulars to which we refer. We may hereafter digest the returns to the circular from the Northern and Eastern States.

1. Commencing with VIRGINIA, the returns from it are utterly unimportant. Mr. Points, of Staunton, enumerates horses, cattle, mules, sheep, swine, poultry, wheat, barley, oats, rye, buckwheat, corn, wool, hops, wax, potatoes, hay, flax, hemp and tobacco, among the agricultural products. Flour and tobacco principal exports. Manufacture of iron increased 10 per cent. since 1842.

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