after a short time, deposits the India-rubber. It dissolved a little amber, but only sufficient to colour the oil red. It also dissolves a small portion of copal in its natural state, but after roasting, the copal dissolves in it as it does in other oils.
USE FOR GAS-MAKING
The crude oil was tried as a means of illumination. For this purpose, a weighed quantity was decomposed, by passing it through a wrought-iron retort filled with carbon, and ignited to full redness. The products of this decomposition were received in a suitable apparatus. It produced nearly pure carburetted hydrogen gas, the most highly illuminating of all the carbon gases. In fact, the oil may be regarded as chemically identical with illuminating gas in a liquid form. The gas produced equalled ten cubic feet to the pound of oil. It burned with an intense flame, smoking in the ordinary gas jet, but furnishing the most perfect flame with the Argand burner.
These experiments were not prosecuted further, because it was assumed that other products, now known and in use, for gas-making, might be employed at less expense for this purpose, than your oil. Nevertheless, this branch of inquiry may be worthy of further attention.
DISTILLATION AT A HIGHER TEMPERATURE
The results of the distillation at a regulated temperature in glass led us to believe that in a metallic vessel, capable of enduring a high degree of heat, we might obtain a much larger proportion of valuable products. A copper still, holding five or six gallons, was therefore provided, and furnished with an opening, through which a thermometer could be introduced into the interior of the vessel. Fourteen imperial quarts (or, by weight, 560 ounces) of the crude product were placed in this vessel, and the heat raised rapidly to about 280° C. (= 536° F.), somewhat higher than the last temperature reached in the first distillation. At this high temperature the distillation was somewhat rapid, and the product was easily condensed without a worm. The product of the first stage was 130 ounces (or over 28 per cent.), of a very light-coloured thin oil, having a density of .792. This product was also acid, and as before, the acid was easily removed by boiling with fresh water. The temperature was now raised to somewhat above 300° C. (=572° F.), and 123 ounces more distilled, of a more viscid and yellowish oil, having a density of .865. This accounts for over 43 per cent. of the whole quantity taken. The temperature being raised now above the
boiling point of mercury, was continued at that until 170 ounces, or over 31 per cent., of a dark brown oil had been distilled, having a strong empyreumatic odor. Upon standing still for some time, a dark blackish sediment was seen to settle from this
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