332 On the Chemical Evidence 



Frederick Accum, Esq. M.R.I. A., Sfc, and Lecturer on 

 Chemistry at the Surry Institution, was next called. He was 

 examined by Mr. Serjeant Lens, and gave the following testi- 

 mony : — That fresh whale oil would emit inflammable gas at 

 600°, but not at a lower temperature ; that in a pan similar to 

 the one used at Messrs. Severns*, if it contained 1 00 gallons of 

 oil, it would take a man at least eight or ten hours to raise it 

 to that temperature ; that he had also made experiments upon 

 some oil which had been in constant use, that is, heated and 

 cooled three times a week for nineteen months, and from this oil 

 he could obtain gas at 460°, similar to the common gas used for 

 illumination ; that if an explosion of oil gas had taken place in 

 the fill-house, as supposed, the explosion would have been heard 

 all over London, and that the oil-vessel would have been lace- 

 rated in pieces. He also said, that new oil contains mucilage 

 and water, which are carried away before it acquires a great 

 heat ; consequently, old oil, which has been frequently heated, 

 and from which these matters have been expelled, will become 

 hot sooner than new oil. Mr. Accum's testimony respecting 

 the certainty of the escape up the steam-vent of any gas that 

 might have been emitted from the oil ; the impossibility of the 

 fire having been occasioned thereby ; and the greater safety of 

 the new process, when compared with the old one of boiling 

 sugar, was similar to that which had been given by several of 

 the preceding witnesses. 



Observations. — Upon Mr. Accum*s testimony respecting 

 the temperature at which he obtained inflammable gas from the 

 oil which had been heated for nineteen months, I am under the 

 necessity of saying that he must either have been deceived as 

 to the nature of the oil which had been sent to him, or there 

 must have been some mistake in the manner of conducting the 

 experiment ; as several of the chemical gentlemen, who, like my- 

 self, were engaged for the plaintiffs in this action, have agreed 

 with me in asserting that inflammable gas cannot be procured 



interior of the steam-bin, and that the steam-bin had a direct communi- 

 cation with the common atmosphere. 



