About 15 per cent. of a very thick, dark oil completed this experiment. This last product, which came off slowly at about 750° F., is thicker and darker than the original oil, and when cold, is filled with a dense mass of pearly crystals. These are paraffine, a peculiar product of the destructive distillation of many bodies in the organic kingdom. This substance may be separated, and obtained as a white body, resembling fine spermaceti, and from it beautiful candles have been made. The oil in which the crystals float is of a very dark colour, and by reflected light is blackish green, like the original crude product. Although it distills at so high a temperature, it boils at a point not very different from the denser products of the first distillation. The paraffine, with which this portion of the oil abounds, does not exist ready-formed in the original crude product; but it is a result of the high temperature employed in the process of distillation, by which the elements are newly arranged. I am not prepared to say, without further investigation, that it would be desirable for the company to manufacture this product in a pure state, fit for producing candles (a somewhat elaborate chemical process); but I may add that, should it be desirable to do so, the quantity of this substance produced may probably be very largely increased by means which it is now unnecessary to mention. Paraffine derives its name from the unalterable nature of the substance, under the most powerful chemical agents. It is white, in brilliant scales of a greasy lustre; it melts at about 116°, and boils at over 700° F.; it dissolves in boiling alcohol and ether, and burns in the air with a brilliant flame. Associated with paraffine are portions of a very volatile oil, _eupione_, which boils at a lower temperature, and by its presence renders the boiling point of the mixture difficult to determine. I consider this point worthy of further examination than I have been able at present to give it, i.e., whether the last third, and possibly the last half, of the petroleum, may not be advantageously so treated as to produce from it the largest amount of paraffine which it is able to produce. The result of this graduated distillation, at a high temperature, is that we have obtained over 90 per cent. of the whole crude product in a series of oils, having valuable properties, although not all equally fitted for illumination and lubrication. A second distillation of a portion of the product which came over in the later stages of the process (a portion distilled at about 650° F., and having a high colour), gave us a thin oil of density about .750, of light yellow colour and faint odour.