on the late Trial of an Insurance Question. 5 



All these circumstances combined, prove that what the plaintiffs' 

 witnesses asserted, that oil undergoes no change, is not correct; 

 for aciueous vapour, combined with acetic acid and carbonic acid 

 gas, is formed, and carbon is deposited. This could not take 

 place, and 1 think no one will dispute it, if the oil did not under- 

 go decomposition. 



Of its being rendered more inflammable bv the change it has 

 inidergnne, I can only observe, that on tliis point the evidences 

 of the plaintiffs' witnesses are at variance among themselves. 

 Mr. Wilson, Dr. Thomson, Mr. Parkes, and otliers, observed, 

 that there was no difference between old and new oil, as they 

 were termed, in their combustibility. The latter said that old oil 

 became less combustible ; and this he did not state from actual 

 experiment, but he assumed it because the oil became thicker. 

 Mr. Brande on the contrary said, that he obtained inflamniable 

 vapour 50 degrees lower from old oil than from new ; and Mr. 

 Accuni stated, that from oil that had been heated for some con- 

 siderable time he had obtained inflauimable vapour as low as 

 4()0 degrees ; but he did not attribute its inflammability to its 

 being old, but to its having been heated in a leaden vessel, and 

 having dissolved a portion of the lead which, in his opinion, 

 rendered it more combustible. Without adverting to any of the 

 assertions made on the other side, as to the change which oil 

 undergoes at the continued beat of 360, I think I have proved 

 on their own admission, that oil does not remain the same ; 

 that a decomposition does take place; and that, new compound.s 

 being formed, it must necessarily undergo a greater change than 

 merely becoming darker and thicker. 



The next point for consideration is the change which takes 

 place in the combustibility of oil at a higher heat. At 600 de- 

 grees, it is stated by Mr. Wilson on the plaintiffs' side, a small 

 quantity of vapour is given out, but none below that heat : if a 

 light were applied to it, it burned with a blue lambent flame and 

 soon went out. About a foot high it would become condensed, 

 and fall back again as oil. This was corroborated by Dr. Thom- 

 son, Mr. Brande, and many others, with slight modifications. 

 The feeble testimony of so humble an individual as myself, in 

 opposition to such high authority as that which I have already 

 (pioted, or in addition to the assertions of the equally high au- 

 thority on the other side, may have but little weight with those 

 who have already formed, or are to form, tiicir judgement upon 

 this subject : but it was a matter of no small surprise to me, whilst 

 in Court, to hear that statement made, when but a very few days 



th;it is fonni.'d during the process of heating oil. This does not alter my ob- 

 jections ; but renders it the more extraordinary, tlmt with the knowledge of 

 thi:> circiimstunce, it should be asserted tluit oil undergoes no cliangc 



beford 



