266 On the Volatility and InflammabllUy 



the gas, if any were formed, would be gradually carried off by 

 the tube. It would require a good deal of time, and much la- 

 bour, to raise the heat to 6 or 700 degrees of Fahrenheit. Such 

 heat would decompose the sugar; and if, in consequence, gas 

 were produced, it would find its way through the steam-vent, and 

 out of the house. If the heat were increased even to 400 de- 

 grees, it would be at the risk of decomposing the sugar, and con- 

 verting that article into gas. Looking to the construction of 

 the machine and of the house, he did not think that any explo- 

 sion could have taken place by any gas which one apparatus of 

 that kind could have produced. He conceived that the gas from 

 the lamps in the manufactory was infinitely more dangerous than 

 any that could, have been generated in the retort. He visited 

 and examined the ruins some time ago, to discover whether there 

 was any trace of an explosion ; but he could not perceive a fissure 

 in any part of the premises, or the least appearance of any con- 

 cussion having taken place. Fixed oils, train-oil, linseed-oil, 

 &;c., were so called to distinguished them from the essential or 

 volatile oils which were produced by distillation. The former 

 required a great degree of heat before they could be converted 

 into vapour, while the latter went off in the most rapid manner. 

 There were no two things in nature more different than fixed and 

 volatile oils. 



J. Barry, Esq. stated, that he was a practical chemist, and had 

 examined the model before the court. The new mode of sugar- 

 refining was much safer than that formerly adopted. In the first 

 place, it avoided that temperature of heat at which sugar was 

 liable to boil over or to catch fire in the pan. Sugar would boil 

 over at 2.50 or 2G0 degrees, whereas oil required 650 or 700 de- 

 grees to accomplish that object. He had seen a very inflamma- 

 ble gas formed from oil at the temperature of 5G5, but not in any 

 great quantity. It required more than fiOO degrees to produce 

 any large portion of gas. Mr. Wilson's method of refining sugar 

 was by far the best, because there was no fire under the pans, 

 and the heat could be so easily turned off. If, in consequence of 

 any negligence, gas were generated in the retort, it would not be 

 sufficient in quantity to do any mischief. It would be discharged 

 into the steam-vent, whence it would immediately escape. He 

 knew of no instance of inflammable gas being heavier than com- 

 mon air. Sugar would emit a light gas at about 330 degrees. 

 He found oil, after being touch boiled, produce gas at rather a 

 lower temperature than it did when new. New oil produced gas 

 at 5S5 degrees, old oil at 568. 



Cross-examined. — Permanent inflammable gas was not a sci- 

 entific term. It had not been used by him. 



Mr. 



