sugar, and the mixture kept for a length of time at a moderate temperature, the whole will be converted into vinegar, without any sensible fermentation. The composition of vinegar being carbon 4+water 3, it follows, that in this conversion one atom of the sugar must produce three of the vinegar or acetic acid, and one of water, which is found to be the case.

Muscovado sugar, of commerce, is sugar in the state in which it arrives from the colonies, in other words, sugar mixed up with variable proportions of foreign matters. According to an analysis made by Avequin, 20lbs. of badly cured Muscovado sugar contained, of silica 414 grains, biphosphate of lime 351 grains, phosphate of lime 300 grains, carbonate of lime 38 grains, organic matter 875 grains, sulphate of potash 291 grains, chloride of potassium 400 grains, acetate of potash 360 grains, acetate of lime 250 grains; amounting, altogether, to about 3 per cent.

In this analysis, it is not the amount of these matters which strikes us as extraordinary, for that is not greater than the nature of the soil from which this mixture of sugar and molasses was produced would lead us to expect, nor is it greater than what is found in the best kinds of sugar which we receive from the West Indies, but it is the excess of the phosphates of lime in proportion to the quantity of the other salts which renders this result an unusual one.

West India sugars always contain a quantity of insoluble impurities, which are immediately precipi

tated when the sugar is dissolved in water. They consist of the earthy matters which have adhered to the canes, of broken up woody tissue, of cellulose, and of coagulated albumen. Their combined amount varies from 2 to 6 per cent, the general average being about 3 per cent. The sugar, when deprived of these substances, contains chlorine, acetic acid, and sulphuric acid, lime, potash, soda, alumina, and silica, the collective amounts of which are from 0.5 to 2.5 per cent.

Molasses may be considered to be the mother liquor which is left after the crystallisation of cane-syrup. This substance must, consequently, consist of sugar in a state of solution, and of all the soluble matters contained in the cane-juice, which have not remained in the sugar, or which may not have been removed during the process of concentration. Its specific gravity is 1330 or 1340, that is about 38° to 39° Beaumé. Avequin's analysis of molasses obtained from canes grown in Louisiana gives, as a result from 20 lbs., good crystallisable sugar 15 lbs., salts and organic matter 1 lb., and 4 lbs. of water. The salts he describes as acetate of potash, chloride of potassium, sulphate of potash, biphosphate of lime, silica, and acetate of lime. And the organic matter, gum, or a substance resembling it; which, however, constitutes only of the foreign matters, and but 65 per 100 of the whole. This analysis, however, does not agree exactly with those obtained from molasses produced from canes grown in those islands of the West Indies which have long been cultivated;

Barbadoes' molasses, for instance, contain both a much larger quantity of organic matter, precipitable by the diacetate of lead, and a much smaller amount of fixed salts.

Treacle is the ultimate product obtained after the various manipulations to which sugar is submitted by the refiner. It is a viscid and adhesive fluid of a dark brown colour, approaching to black, and has a specific gravity of about 1380 or 1400, varying from 42° to 44° Beaumé, at the ordinary temperature of England. By evaporation it becomes solid, but in a short time reverts to its original fluid state. It cannot be made to crystallise, but on repose often deposits a small quantity of a light-coloured amorphous sugar. Boiling alcohol separates from it a small quantity of crystallisable sugar, while it at the same time produces the precipitation of a considerable amount of a substance resembling gum. Cold alcohol dissolves from treacle, when dried, a compound of a dark colour, of a sweetish saline taste, and which is very deliquescent and perfectly uncrystallisable. It appears to be a combination of saline matter and a substance which will be noticed hereafter, and which is known as the "matière deliquescente" of Hervey. Besides these bodies, treacle likewise contains a certain amount of uncrystallisable sugar or glucose, a little mannite, and melasinic and ulmic acids, on which its intense colour depends.

CHAP. III.

SUGAR-CANE, ITS ANATOMY AND PHYSIOLOGY.
COMPOSITION

AGENTS.

CANE-JUICE, ITS - THE CHANGES PRODUCED UPON IT BY REALTERATIONS EFFECTED DURING THE LIFE OF THE METHODS EMPLOYED TO ASCERTAIN THE QUANTITY OF SACCHARINE MATTER IN LIQUIDS.

THE PLANT.

THE SUGAR-CANE (saccharum officinarum) belongs to the graminacea or grass tribe of plants, all of which are of endogenous growth, and are generally of very simple structure.

There are many varieties of sugar-cane cultivated in the West Indies, Brazil, Louisiana, and the Mauritius, the principal of which are — - 1st, the common, or, as it is generally called, the Creolecane, from having been the one originally introduced into the New World; 2d, the yellow Bourbon; 3d, the yellow Otaheite. The two latter are frequently confounded, and are, at present, probably from the influence of soil and climate, not easily distinguished. The other varieties are 4th, the Otaheite with purple bands; 5th, the purple Otaheite; and 6th, the transparent or ribbon-cane, known by its dark red streaks on a clear waxylooking ground.

To discuss the merits or demerits of each of them belongs to the province of the agriculturist. We have another object to perform, namely, that

owe the property of separating carbonic acid into its two elements, and of eliminating the oxygen. The name of chlorophille has been given to it; and according to Mulder, it consists of carbon 18, hydrogen 9, oxygen 8, and nitrogen 1, in atoms.

A vertical section of a sugar-cane similarly examined, demonstrates a like organisation to the one just described. It also permits us to obtain a more distinct notion of the mode of arrangement of the different parts than we could otherwise have. When the plant has acquired a certain age its vessels are seen to be hidden by the thin surrounding envelope of woody fibre, incrusted with the before-mentioned "matière" of Payen, and it is with difficulty that we can procure a distinct view of them. But if we examine a similar section taken from a newly formed joint, into the tissues of which the "matière incrustante" has not been deposited, the vessels may be most distinctly seen by the aid of a tolerably good microscope. They are found running together in bundles of two, three, or four, and preserving a perfectly straight course parallel to the axis of the stem. They appear to be formed of a succession of rings, and resemble somewhat the windpipes of some animals; hence they have sometimes been denominated annulated vessels, and occasionally trachea. They pass directly along the joint from its lower to its upper extremity, without presenting any appearance of anastomosis, or any other communication with each other. At the knot or point of junction of two joints, however, there is a complete lacework of vascular tubes, some of which are curved or looped, others run horizontally towards