CnEMISTRT. 205 



would particularly call the attention of the society to the Hict tliat 

 such mixtures are more likely to be formed in what are called 

 empty cans, which have contained hydrocarbons, and, from their 

 supposed emptiness, are imagined by i^i^norant peoj^le to be free 

 from danger. A light may be applied with but little or no dangor 

 to a vessel full of gasoline or gasoline vapor, or even such a mix- 

 ture of vapor and air as would produce lighting gas ; but in case 

 the vapor be mixed with a suflicient quantity of air, it would iu- 

 stantly explode." 



A writer in the " Boston Journal of Chemistry " makes tlie fol- 

 lowing statement: " Kerosene accidents occur from two causes: 

 First, imperfect manufacture of the article ; second, adulterations. 

 An imperfectly manufjictured oil is that which results when the 

 distillation has been carried on at too low temperature, and a por- 

 tion of the naphtha remains in it. Adulterations are largely made 

 bj' unprincipled dealers, who add 20 to 30 per cent, of naphtha 

 after it leaves the manufacturer's hands. The light naphthas 

 which have been spoken of, as known in commerce under the 

 names of benzine, benzoliue, gasoline, etc., are very volatile, in- 

 flammable, and dangerous. They, however, in themselves, are 

 not explosive ; neither are they capable of furnishing any gaSy 

 when placed in lamps, which is explosive. Accidents of this na- 

 ture are due entirely to the facility with which vapor is produced 

 from them at low temperatures. But the vapor by itself is not 

 explosive ; to render it so, it must he mixed with air. A lamp may 

 be filled with bad kerosene, or with the vapor even, and in no 

 possible way can it detonate, or explode, unless atmospheric air 

 has somewhat got mixed with vapor. A lamp, therefore, full, or 

 nearly full, of the liquid, is safe ; and also one full of pure warm 

 vapor is safe. ExjDlosions generally occur w^hen the lamp is first 

 lighted, without being filled, and late in the evening, when the 

 fluid is nearly exhausted. The reason of this will readily be seen. 

 In iising imperfect or adulterated kerosene, the space above the 

 line of oil is always filled with vapor; and so long as it is warm, 

 and rising freely, no air can reach it, and it is safe. At bed-time 

 when the family retire, the light is extinguished ; the lamp cools, 

 a portion of the vapor is condensed ; this creates a partial vacuum 

 in the space, which is instantly filled with air. The mixture is 

 now more or less explosive ; and w'hen, upon the next evening, 

 the lamp is lighted without replenishing with oil, as is often done, 

 an explosion is liable to take place. Late in the evening, wiien 

 the oil is nearly consumed, and the space above filled with vapor, 

 the lamp cannot explode so long as it remains at rest upon the 

 table. But take it in hand, agitate it, carry it into a cool room, 

 the vapor is cooled, air passes in, and the vapor becomes explo- 

 sive. A case of lamp explosion came to the waiter's knowledge 

 a few years since, which was occasioned b}^ taking a lamp from 

 the table to answer a ring of the door-bell. The cool outside air 

 which impinged upon the lamp in the hands of the lady rapidly 

 condensed the vapor, air passed in, explosion occurred, which re- 

 sulted fatally. If the lamp had been full of fl-uid, this accident 

 could not have occurred. Before carrying it to the door, flame 



18 



