CHEMICAL SCIENCE. 235 



through the cover, and occupies such a position that its bulb cornea 

 within a short distance from the bottom of the reservoir. In order 

 to determine the temperature at which the oil gives off sufficient 

 vapor to cause an explosion, the oil to be tested is poured into the 

 reservoir, the wick is lighted, and the instrument placed on a stove 

 or over the flame of a lamp. At a temperature which varies in pro- 

 portion to the quantity of explosive ingredients contained in the oil, 

 the vapor is given off, and, mixing with the air in the reservoir, 

 passes up through the space between the wick tube and the larger 

 tube, and explodes when ignited by the flame, thereby extinguishing 

 the light. The height of the mercury in the thermometer will deter- 

 mine the quality of the oil. 



The contrivance is very simple and cheap, and enables any one to 

 ascertain in a few minutes whether an oil is of a quality to be burned 

 with safety. 



Explosiveness of Mineral Oils. From investigations into this sub- 

 ject recently made in England, it appears that no danger can arise 

 from the use of petroleum or coal-oil if it be properly refined. To ascer- 

 tain whether this necessary process has been effectively performed, it 

 is only necessary to place the oil in an open dish in a water-bath, and 

 heat it to a temperature of one hundred and thirty degrees. If when 

 elevated to this heat it does not ignite by the application of a match, 

 it is safe ; but any oil igniting at a temperature below one hundred 

 and thirty degrees is dangerous, and should not be used for domestic 

 purposes. 



English Legislation respecting Mineral Oils. By an act passed by 

 the British Parliament, in 1862, it is provided that " not more than 

 forty gallons of petroleum, which, by the first section of the said act, 

 it is declared shall include any product thereof that gives off an in- 

 flammable vapor at a temperature of less than one hundred degrees 

 of Fahrenheit's thermometer, shall be kept within fifty yards of a 

 dwelling-house, or of a building in which goods are stored, except in 

 pursuance of a license given by the local authority ; and any petro- 

 leum kept in contravention of that section will be liable to forfeiture." 



Petroleum Trade. The rapid and extended use of American 

 petroleum has no parallel in the history of manufactures or commerce. 

 It was in August, 1859, that petroleum was first obtained in very con- 

 siderable quantity in the valley of " Oil Creek," Pennsylvania; and 

 since then the obtaining of the oil from the wells, the refining of it, 

 and its transportation to markets, have continued to form a new and 

 immense business. In the first nine months of 1861, the exports of 

 American petroleum amounted to 368,940 gallons ; while in the first 

 nine months of 1862 the exports amounted to 6,294,819 gallons an 

 increase of 5,925,879 gallons. A circular recently issued by a lead- 

 ing oil-broker of Liverpool says: "The oil exported from America 

 and Canada in 1862 (the first year of its European introduction) ex- 

 ceeded in value 1,000,000. Yet one tithe of its dissemination is 

 not effected; Britain has manipulated pretty freely, so have France 

 and the German States, but so clamorous are they for more that the 

 export extension cannot be made sufficiently general. Spain, Portu- 

 gal, Italy, and Russia, have yet to receive it in the crude form." 



