vague; and besides, that it is founded on no experiment, direct or indirect. In this hypothesis too we must imagine a compound altogether new, sugar combined with a substance that renders it insoluble in cold water; and sugar has never yet presented us with such a compound.

Others have supposed, that heat alone is capable of effecting this conversion of fecula into saccharine matter; a fact which, if it were confirmed, might throw fresh light on the saccharine fermentation of Fourcroy.

Accordingly, starch has been boiled with water four days in succession, till it became extremely fluid. The filtered liquor was evaporated, and the result was a thick mucilage, very bitter, without the least taste of sugar. The starch remaining on the filter resisted the action of boiling water, and exhibited a very hard horny

matter.

It remains to be examined, therefore, whether the sulphuric acid, or the starch itself, be decomposed.

To judge by the letter from Petersburg, the Russian chemists seem to suppose that a decomposition of the sulphuric acid takes place.

To account for these phænomena, we should operate in close vessels. Accordingly the author we have referred to introduced into a tubulated receiver a hundred grammes of sugar of milk, four of sulphuric acid, and four hundred of water. To the neck of the retort was adapted a tubulated receiver, from which proceeded a sigmoid tube, opening under a jar filled with water.

After boiling for three hours, no gas had come over, except the air contained in the vessels. A piece of blue paper introduced into the neck of the retort, was not reddened. The water that had passed into the receiver was without taste, did not redden litmus paper, had no smell of sulphureous acid, and did not precipitate lime-water, muriat of barytes, or acetat of lead; consequently it contained no sulphureous, sulphuric, acetic, or carbonic acid; in short, it was nothing but pure water.

Barytes-water traversed by the bubbles, extricated during the process, was not rendered turbid in the least, and the gas that had passed into the jars was nothing but the air of the vessels.

It is evident, that the sulphuric acid had not undergone the

slightest decomposition: nevertheless, the sugar of milk was decomposed: it had a much more saccharine taste, and after saturation with chalk it fermented very readily with yeast.

It was necessary, therefore, to examine the decomposing action of the sulphuric acid on the substances in question. For this purpose the same experiment was begun afresh in close vessels, with 100 grs. of sugar of milk, 400 grs. of water, and four grains of sulphuric acid. During the process no gas was evolved, as in the preceding experiment.

The liquid was then concentrated in a dish accurately weighed, after having added five grs. of potash, to saturate the acid.

The mass thus evaporated to dryness should have weighed 109 grs, in consequence of the 100 grs. of sugar of milk, 4 grs. of sulphuric acid, and 5 grs. of potash employed; but it weighed only 98 grs. consequently there was a loss of 11 grains. This experiment was repeated twice more, and there was still a loss of 9 or 11 grs. giving a mean of 10 grs.

This loss is too great to be ascribed to any error in the weighing, which was conducted with the greatest care.

Hence we may conclude, that this diminution of weight is occasioned by a quantity of water formed at the expense of the sugar of milk; and this with the more reason, as no gas, no acid, and no other volatile substance, was extricated during the boiling.

All these experiments with the sugar of milk were equally repeated with starch, except that a much larger quantity of water was added, to prevent it from burning. The results were the same as those obtained with sugar of milk.

Conclusions. From all that has been said, it follows:

1. That starch and the fecula of potatoes, boiled with water acidulated with sulphuric acid, are converted into a liquid saccharine matter, the quantity of which corresponds with the weight of the starch employed.

2. That this saccharine matter is susceptible of the alcoholic fermentation.

3. That the syrup of starch is composed of gummy matter and saccharine matter in variable proportions.

4. That the syrup evaporated slowly in a stove exhibits an elastic substance, perfectly transparent.

5. That the gummy matter exhibits all the characters of a tree gum, except that of forming mucous acid by means of the nitric. 6. That neither this gum, nor the saccharine matter, holds sulphuric acid in combination.

7. That the heat of boiling water alone is insufficient to convert starch into saccharine matter, as nothing is obtained but a bitter matter, and a horny substance insoluble in boiling water.

8. That sugar of milk treated with two, three, four, or five hundredths of sulphuric acid is converted into confused crystals, which have an extremely saccharine taste, and are susceptible of the alcoholic fermentation.

9. That this saccharine matter does not contain any sulphuric acid in combination.

10. That the muriatic acid effects the same changes in sugar of milk.

11. That neither the nitric nor acetic acid converts sugar of milk into fermentable sugar.

12. That sugar of milk thus converted into fermentable sugar becomes very soluble in alcohol.

13. That sulphuric acid is not decomposed in its action on starch and sugar of milk: and that, from the facts mentioned, it is much more probable, that the acid takes from these substances oxygen and hydrogen in the proportions necessary to form water.

We have only to add, that the preceding experiments have been repeated in our own country with similar results: but that, however curious such results may be as matter of chemical information, neither the quantity nor the quality of the sugar hereby produced can ever render it worth while to persevere in the same process, except in the case of an utter dearth of West-Indian or even East-Indian produce.

Sugar Candy.

This well-known material is nothing more than sugar brought to a regular form by slow crystallization. The management of it differs considerably from that of loaf sugar. To prepare it, the syrup is clarified as usual, and boiled down to a certain point, but not so much as for making loaf sugar. It is then poured into large