of Fish Oil 259 



it would send out no permanently inflammable gases. To bring 

 about such a degree of heat would require several hours of hard 

 firing, and could never take place from negligence alone. If a 

 similar fire were placed under sugar, inflammable gases would 

 be produced in a much shorter time. If produced in this retort, 

 they would go up the steam-pipe, a vent which was rendered 

 necessary for discharging the air within the vessel; and in oil 

 there was also a quantity of aqueous matter, which it was ne- 

 cessary to carry off in the same manner: conducted through the 

 pipe to which he alluded, it all passed out at a lateral aperture 

 in the chimney. All draught down the chimney was carefully 

 guarded against, and the brick-work of the chimney secured 

 against heat by cast-iron pipes. He thought there was no dan- 

 ger from the gas that might escape mixing with the atmospheric 

 air, because the proportion necessary to cause explosion must be 

 one to six or seven, and it was impossible that such a proportion 

 should oe formed even in the fill-house. This danger was much 

 greater with the ordinary process. The vent was quite sufficient 

 to carry out ten times the quantity of gas which could be pro- 

 duced by this apparatus. The retort had been repaired a few 

 days before. With regard to the oil changing its quality, because 

 it became thicker by use, he did not think that that increased its 

 tendency to become inflammable. He was present at an exami- 

 nation of the apparatus with several surveyors and engineers after 

 the fire had happened ; there was not the slightest rent or fissure 

 in the retort, and a four-inch wall on one side of it was as per- 

 pendicular as when originally built. There was a great quantity 

 of rubbish upon it, and a piece of fused brass which had come 

 from above ; but he could not discover, from the appearances 

 around, the slightest indication of an explosion having taken 

 place. The screws of the aperture were perfect, and the thread 

 bright and sharp. The pump was much fused, and the copper ves- 

 sel melted — a circumstance to be accounted for by the coals kept 

 under it for the purpose of cutting off the draught. The pipes 

 were of copper, and could not burst from the pumping of the oil, 

 because the valves were smaller than their diameter : in the inside 

 of the retort there was a quantity of carbonaceous matter, na- 

 turally resulting from the gradual distillation of the oil, and ex- 

 plosion would have caused a different appearance. 



Cross-examined. — He had taken out three patents for the pro- 

 cess which he had been describing — one in 18J6, one in 1817, 

 and the third in 1818. Previous to this invention he had been 

 engaged in chemical manufactures. His patent had been applied 

 to four cases; two of them occurred at Liverpool, but in both of 

 these tallow was used as well as oil. He had put up his appa- 

 ratus for another fiousc in London about six months ago, but it 



S 2 was 



