tention, numerous individuals, some of whom were engaged in the manufacture of kerosene (see Kerosene), began to experiment with petroleum with a view to obtain materials resembling the products that were then being distilled from coal. These earlier experiments and the small cost of producing kerosene from this source very soon led to the substitution of petroleum for coal as the crude material for illuminating oil, and almost all the manufacturers changed their apparatus and establishments into petroleum refineries. The high price of kerosene at that time left such a very wide margin for profit that the methods of carrying on the business, crude as they were in almost every particular, were still very successful. In 1861, three years after petroleum first attracted special notice, there were refineries in nearly every city on the Atlantic coast, from Baltimore to Portland, and the oil regions were full of them; but it was four years later before coal was entirely disused in one or two establishments. For several years the only petroleum product considered of value was kerosene. The light and heavy products were either used as fuel or thrown away. As the profits of the business were lessened from extensive competition, attempts were made to utilize the “by-products.” One after another found useful applications, until now at least ten commercial articles are obtained, and some of them are consumed in enormous quantities. These are:
| ARTICLES. | Sp. gr. | Baumé. | Boiling point. |
| Rhigolene | .625 | . . . | 65° F. |
| Gasolene | .665 | 85° | 120 |
| C Naphtha | .706 | 70 | 180 |
| B Naphtha | .724 | 67 | 220 |
| A Naphtha | .742 | 65 | 300 |
| Kerosene | .804 | 45 | 350 |
| Mineral sperm oil | .847 | 36 | 425 |
| Neutral lubricating oil | .883 | 29 | 575 |
| Paraffine lubricating oil | . . . | . . . | . . . |
| Paraffine wax | .848 | . . . | . . . |
| Residuum | . . . | . . . | . . . |
Rhigolene is the most volatile fluid that can be produced by condensing the first portions distilled from gasolene in a mixture of ice and salt. It is the lightest of all known fluids, and its evaporation at ordinary temperatures is so rapid as to cause the mercury to descend to −19° F. in 20 seconds. It was prepared at the suggestion of Dr. H. J. Bigelow of Boston, and has been used to a considerable extent for producing local anaesthesia in surgical operations. Gasolene is the lightest product from petroleum that is produced in large quantities. It is used in the carburetters of automatic gas machines, and is admirably adapted to such purposes. A, B, and C naphthas are applied to a variety of uses in mixing paints and varnishes, and dissolving resins and other substances; but they have little commercial value, as their uses are quite limited. Kerosene has already been discussed. (See Kerosene.) Mineral sperm is the name given by Joshua Merrill, of the Downer kerosene oil company, to a petroleum product discovered by him. This is an illuminating oil intermediate in density between kerosene and lubricating oil. It is volatile only at very high temperatures, and is consequently free from the objections that have been urged against more easily inflammable oils. As this oil has very little odor and will not take fire at any temperature below 300° F., it is especially valuable for use on railroads and ocean steamers. Neutral lubricating oil is another product discovered by Mr. Merrill. He has prepared it of a light straw color, and with but little more taste or odor than sweet oil of almonds. It is by far the most pleasing and valuable lubricating oil yet prepared from any mineral source. The so-called paraffine lubricating oils, though of about the same density, contain a certain proportion of lighter and more volatile oils, which have a very pungent odor and burning acrid taste. These are unavoidably formed during the distillation of the heavier portions of the crude petroleum. By distilling in such a manner that the oils are never heated above their boiling points, this lighter oil is removed, and the neutral odorless oil is left in the still. Mixtures containing as much as 80 per cent. of this oil to 20 per cent. of sperm or other animal oil have the odor and taste of the animal oil. Both these mixtures and the pure oils have been used instead of the animal oils in immense quantities for oiling wool and machinery, the latter being considered especially valuable for oiling spindles in cotton mills. The ordinary paraffine lubricating oils are of various qualities, much depending upon the care and expense involved in their preparation. Those prepared by simply fractioning the distillate from petroleum are dark-colored, of very rank disagreeable odor, and are adapted to comparatively few uses, while some of the better qualities are nearly as valuable as the neutral oil prepared by Mr. Merrill. Paraffine wax has been described elsewhere. (See Paraffine.) Residuum is the black residue remaining in the still from the distillation of crude petroleum. It is used by the manufacturers of paraffine and lubricating oils, and also to a limited extent for lubricating heavy journals. — The crude oil is stored in large, often enormous wrought-iron tanks. When it is shipped in wooden barrels they are coated with glue upon the inside. For transportation on long voyages the lighter products, including kerosene, are put up in tin cans holding five gallons each, and hermetically sealed by soldering on the cover. The crude oil, as it flows from the wells or pumps, is received into large tanks, where it is allowed to stand for some time in order that the water may separate and settle to the bottom. When the wells are some distance from a railroad track, the oil is often transported to the track by being forced through a pipe laid along the ground. Large quantities have been floated down the Alleghany river in
