114 Mr. Parkes' additional Observations 



high, had become so full of vapour, which was so disa- 

 greeable and oppressive to the lungs, that I could not breathe 

 in it. It is further observable, that this experiment was made 

 in a part of the newly-erected sugar-house, before any of the 

 windows had been put in, or the outer door hung; circum- 

 stances which allowed of the escape of much of the vapour 

 into the atmosphere. 



When the oil had acquired the temperature of nearly 580°, 

 Mr. Dalton also was obliged to desist from carrying a light 

 to the orifice of the safety tube, the suffocating effect of the 

 oil vapour was so intolerable. ^ 



It was now found very .difficult to raise the temperature, 

 though the draught of the fire-place was very great, and the 

 fire was made as large as possible. Still, Mr. Wilson and 

 Mr. Cooper persisted in going every five minutes across the 

 large room already mentioned, to apply a lighted candle or a 

 lighted strip of deal to the end of the safety-pipe : but in none 

 of these trials did these gentlemen find the vapour in the least 

 inflammable. 



During the whole of this time, the stench continued to 

 increase, although the mercury in the thermometers mounted 

 slowly; and when the oil was brought up to 600°, the two 

 gentlemen last named were compelled to say, that they were 

 unable to go through the cloud of vapour any more, for 

 the purpose of applying a lighted candle to the end of the 

 tube. 



Beino- still desirous of prosecuting the experiment as far as 

 possible, we had no means left but to engage two of the men 

 who had long been inured to the heats and offensive smells of a 

 sugar-house, whom we instructed to go with a lantern across 

 the room while we stood on the outside of the door to witness 

 their application of lighted candles to the end of the tube. This 

 was done every five minutes, and we took care every time to 

 place ourselves in such a situation that we could witness their 

 going up to the tube, and applying a light to the orifice. In every 

 trial the vapour extinguished the light, instead of being itself 

 Ignited by it. 



