100 OX THE EXPLOSIB1LITY OF COAL OILS. 



marvellous and incredible. From one of these recent drill-holes, 

 termed " oil-wells," the petroleum gushed up with such violent force 

 as to discharge the stream high in the air, and the flow continued so 

 abundant that it reached the furnace of the steam-engine used for 

 working the drill-rods. Becoming thus kindled, a vast flame lighted 

 up the surrounding country at night. Before the conflagration could 

 be extinguished many hundreds of barrels of petroleum flowed in a 

 blazing flood into the adjacent rivers. In another instance, the reser- 

 voirs of petroleum being tapped by the drills earlier than anticipated 

 and before a supply of empty casks was provided, the gushing stream 

 was turned into a ravine and there collected by a dam to preserve it 

 for use. Over considerable extents of valleys an abundance of pe- 

 troleum has been thus obtained from reservoirs, in which it has been 

 gradually accumulating from the natural process of distillation of 

 bituminous coals in the depths of the earth. The ample supply of pe- 

 troleum available from these sources has cpuite recently reduced the price 

 of it to about fifty cents per barrel, and has nearly superseded recourse 

 to the artificial distillation of bituminous coal. This unexpected gift 

 to the children of men may well excite their wonder and their admira- 

 tion of the provident care in anticipating human wants thus manifested 

 by a bountiful Creator. 



Both the artificial and natural petroleum in- the crude state of a tarry 

 oil are found unfit to be burnt in lamps. After numerous attempts to 

 refine the crude petroleum by a second process of distillation, three re- 

 markably different products were separately oblained. Each one of these 

 three substances having a different evaporative or boiling point, like 

 water and alcohol, they are readily separable during one continued pro- 

 cess of distillation, by gradually increasing the heat beneath the still. 



The first product that comes over from the condenser is the volatile 

 spirits resembling ether and alcohol, called naphtha, benzole, benzine, 

 &c, which boil at a lower temperature than alcohol (about 150 deg. to 

 160 deg. Fahrenheit). Naphtha evaporates as rapidly as ether, pro- 

 ducing similar lethean effects on breathing the vapour, and even ex- 

 ceeds ether and alcohol in inflammability. 



It appears to be the common practice of the distillers of petroleum, 

 or coal tar, to keep the heat beneath the stills very low until this 

 naphtha has time to become evaporated at its boiling point of 160 deg., 

 and to flow, from the condenser in a crystalline stream into a cistern 

 arranged to receive it. When, by the test of a hydrometer, its specific 

 gravity is found to become increased to a certain degree by containing 

 some of the heavier coal oil, the stream from the condenser is diverted 

 into another cistern designed, for receiving the second product of the 

 distillation, being a heavier coal oil, commonly known as " kerosene." 



The exact point where the naphtha becomes exhausted and the kero- 

 sene begins to flow, is a nice question to be decided upon by the dis- 

 tiller. The extreme inflammability of the naphtha renders it unsafe 



