Maech 13, 1896.] 



SCIENCE. 



387 



caused by some other body present and not 

 by the pure acetylene. 



If it is found that phosphoretted hydrogen 

 or some similar impurity is present in 

 dangerous quantity, they can probably be 

 removed by a proper treatment of the gas. 



Arsenuretted hydrogen might also be 

 present, but I have failed to find any trace 

 of it in commercial acetylene. 



It has been said that acetylene gas could 

 never act as a poison, because an escape 

 from a leaky pipe would attract the atten- 

 tion of a person, even while asleep, by its 

 irritating action upon the throat, producing 

 coughing. The statement is contrary to all 

 my observations. 



Further experiments upon this subject are 

 required, but the evidence already accumu- 

 lated seems to be favorable to acetylene as 

 compared with water gas, and if the new il- 

 luminant can be made for a reasonable price 

 and can be quite freed from poisonous im- 

 purities it should become a formidable com- 

 petitor with water gas. On the other side, 

 however, we shall find that the danger from 

 explosion will call for special precautions in 

 the use of acetylene gas. 



DANGER IN USE OF LIQUIFIED ACETYLENE. 



There will be an evident advantage, if 

 acetylene gas lighting succeeds, to begin by 

 introducing it without putting down mains 

 and setting down generating houses ; this 

 can be done by supplying customers with 

 liquified gas. A cylinder holding say 1 ,000 

 cu. ft. gas compressed in a space of less than 

 2 cu. ft. can be attached to the gas pipes of 

 a house in place of a meter. 



This new gas service is, however, not so 

 simple as would at first appear. Two 

 cylinders must be used at once, or at 

 least a second one must be brought before 

 the first is exhausted to make the supply 

 continuous, otherwise we should have the 

 disagreeable surprise of finding the gas ex- 

 tinguished. A gauge on the cylinders must 



be watched to see when No. 1 must be cut 

 off and No. 2 turned on. Neglect in care 

 of this will cause extinction of the gas and 

 discredit of the system. The gas companies 

 have accustomed us to a. constant supply 

 through mains at an even pressure and have 

 set a high standard of convenience. 



The cylinders contain gas at a pressure 

 of 6 to 700 fts. A reducing valve, al- 

 ways kept in order, must reduce this pres- 

 sure to 1 oz.=:2 inches water. The Pintch 

 valve employed on railroad lines is used, 

 but we must ask the question : Will it al- 

 ways keep in order with the care it would 

 get in a private house or tenement house '? 

 Then an escape valve is required in case a 

 fault of the Pintch valve throws the whole 

 pressure on the pipes. A mercury seal 

 would answer to empty the gas into the air, 

 and it could be counted on to work satis- 

 factorily, but the gas would be lost each 

 time that the valves got out of order. 



All this apparatus makes the use of liqui- 

 fied acetylene somewhat complicated, and in 

 addition to this disadvantage it would pre- 

 sent a serious danger in case of fire. The 

 cylinders when strongly heated would be lia- 

 ble to explosion, and it is proposed to guard 

 against this danger by employing a mercury 

 seal to empty them when the pressure exceeds 

 safe limits. This arrangement, even suppos- 

 ing that it always performed its office during 

 a fire, would be open to a serious objection, 

 for if the fire took place in a large building in 

 a town containing, say, 10 cylinders with 

 5,000 cu. ft. of gas in the 10, this quantitj^ 

 of gas thrown in the air would make an ex- 

 plosive mixture with 20 times its volume of 

 air, or about 100,000 cu. ft. in all, and 

 whether disengaged on the roof or in the 

 street would expose the firemert to a new 

 danger. 



If we add to the small annoyances aris- 

 ing from the care of a gas supply which is 

 not constant like that of gas delivered in 

 mains, the danger of explosion of a cylinder 



