By means of this process, which is easy to be put in practice, and of little expence in the execution, syrups may be obtained clear and white (even when produced from black grapes), and of a pure sweetness, free from a certain flavour of molasses and burnt sugar, from which it has not hitherto been found possible to exempt grape syrup, when boiled in the ordinary mode, sufficient for its preservation. Thus this precious production, preserved in bottles and vessels of every size, may be transported to a great distance and in all seasons, coming from Bergerac, Mèze, and all the manufactories of the South, to improve the produce of our small vineyards, and make all classes of society share in the enjoyment of this useful resource. § LVIII. _General Observations._ From this detail of experiments, it is obvious that this new method of preserving animal and vegetable substance, proceeds from the simple principle of applying heat in a due degree to the several substances, after having deprived them as much as possible of all contact with the external air. It might on the first view of the subject be thought that a substance, either raw or previously acted upon by fire, and afterwards put into bottles, might, if a vacuum were made in those bottles and they were completely corked, be preserved equally well with the application of heat in the water-bath. This would be an error, for all the trials I have made have convinced me that the absolute privation of the contact of external air (the internal air being rendered of no effect by the action of heat), and the application of heat by means of the water-bath, are both indispensable to the complete preservation of alimentary substances. My object is not like that of the Bourdeaux chymists, to disunite the component parts of the animal substance, and obtain the animal jelly in a separate state, as well as the animal fibre, free from its juice, and so made to resemble tanned leather. Neither is it my endeavour to furnish at a great expence, as in the preparation of portable soup, a tenacious paste or glue, better adapted to derange the stomach than to provide it with a salutary nourishment. My problem is, to preserve all nutritive substances with all their peculiar and constituent qualities. My experiments prove that I have resolved this problem.[S]