306 Mixter — Products of the Explosion of Acetylene. 



o — o 



diminished slowly and a reddish liquid appeared. A little 

 water was introduced in order to find if phosphoric acid will 

 condense acetylene. The change if any was slight in two days. 

 Owing to an accident the experiment was not completed, but 

 the absorption observed suggests doubt as to the value of 

 phosphorus pentoxide as a drying agent for 

 acetylene. In the remaining experiments no 

 such absorption was observed. 



Experiment 55.— After 8 days the phos- 

 phorus was removed and the pressure in- 

 creased to 3*3 atmospheres and the gas was 

 then sparked. The condensation was 8 per 

 cent and the acetylene remaining was 8 per 

 cent. 



Experiment 59. — A smaller quantity of 

 phosphorus pentoxide was used than before. 

 However, some remained unaltered and after 

 8 days the pressure was made 3 atmospheres 

 and the gas was sparked. The explosion was 

 prompt and apparently as violent as any in 

 the glass U-tubes. 6 per cent of the gas had 

 formed condensation products and the acety- 

 lene in the residual gas was 24 per cent of 

 that taken. 



Experiment 60. — The acetylene stood over 

 a solution of calcium hydroxide 3 days before 

 it was put into the U-tube. The phosphorus 

 pentoxide used filled a tube 2 cm long and l cm 

 wide used to hold it. The phosphorus was 

 also placed in a short tube. When the apparatus was filled 

 the volume of the gas was noted and it did not change appre- 

 ciably in the two weeks the gas was left to dry and to give up 

 traces of oxygen. The gas, 57 cc , was then condensed to 19 cc 

 and sparked by closing the primary for an instant. The 

 explosion was prompt and violent. The condensation was 5 

 per cent and the acetylene in the residual gas was 21 per cent 

 of the gas taken for the test. 



The results obtained with dry acetylene indicate that water 

 is not essential to the explosion of the gas, and that the wide 

 variations noted in the first paper in the products of explo- 

 sions in glass tubes are not to be ascribed to the presence of 

 water. 



The following table gives the number of cubic centimeters 

 of acetylene and hydrocyanic acid per liter of gas in the bomb 

 after explosion. 



